Imaging element, stacked imaging element, and solid-state imaging apparatus

ABSTRACT

An imaging element includes a photoelectric conversion unit including a first electrode, a photoelectric conversion layer, and a second electrode that are stacked, in which an inorganic oxide semiconductor material layer is formed between the first electrode and the photoelectric conversion layer, and the inorganic oxide semiconductor material layer includes at least two types of elements selected from the group consisting of indium, tungsten, tin, and zinc. Alternatively, a LUMO value E1 of a material included in a part of the photoelectric conversion layer positioned near the inorganic oxide semiconductor material layer and a LUMO value E2 of a material included in the inorganic oxide semiconductor material layer satisfy E1−E2&lt;0.2 eV. Alternatively, the mobility of a material included in the inorganic oxide semiconductor material layer is equal to or greater than 10 cm2/V·s.

TECHNICAL FIELD

The present disclosure relates to an imaging element, a stacked imagingelement, and a solid-state imaging apparatus.

BACKGROUND ART

In recent years, a stacked imaging element is drawing attention as animaging element included in an image sensor o=the like. The stackedimaging element has a structure including a photoelectric conversionlayer (light receiving layer) placed between two electrodes. Inaddition, the stacked imaging element needs to have a structure forstoring and transferring signal charge generated in the photoelectricconversion layer based on photoelectric conversion. In a structure inthe past, a structure for storing the signal charge in an FD (FloatingDrain) electrode and transferring the signal charge is necessary, andfast transfer is necessary to prevent delay of the signal charge.

An imaging element (photoelectric conversion element) for solving theproblem is disclosed in, for example, Japanese Patent Laid-Open No.2016-63165. The imaging element includes:

a storage electrode formed on a first insulating layer;

a second insulating layer formed on the storage electrode;

a semiconductor layer formed to cover the storage electrode and thesecond insulating layer;

a collection electrode formed to be is contact with the semiconductorlayer and formed away from the storage electrode;

a photoelectric conversion layer formed on the semiconductor layer; and

an upper electrode formed on the photoelectric conversion layer.

An imaging element using an organic semiconductor material for thephotoelectric conversion layer can photoelectrically convert a specificcolor (wavelength band). Furthermore, in a case of using the imagingelement in a solid-state imaging apparatus, the feature allows to obtaina structure including stacked subpixels (stacked imaging elements) thatis impossible in a solid-state imaging apparatus in the past. In thestructure, the subpixel includes a combination of as on-chip colorfilter layer (OCCF) and the imaging element, and the subpixels aretwo-dimensionally arrayed (for example, see Japanese Patent Laid-OpenNo. 2011-138927). There is also as advantage that demosaicing is notnecessary, and a false color is not generated. In the followingdescription, an imaging element including a photoelectric conversionunit provided on the semiconductor substrate or on an upper side of thesemiconductor substrate may be referred to as an “imaging element offirst type” for convenience. The photoelectric conversion elementincluded in the imaging element of first type may be referred to as a“photoelectric conversion unit of first type” for convenience. Animaging element provided in the semiconductor substrate may be referredto as an “imaging element of second type” for convenience. Aphotoelectric conversion unit included in the imaging element of secondtype may be referred to as a “photoelectric conversion unit of secondtype” for convenience.

FIG. 81 illustrates a configuration example of a stacked imaging element(stacked solid-state imaging apparatus) is the past. In the exampleillustrated in FIG. 81, a third photoelectric conversion unit 343A and asecond photoelectric conversion unit 341A, which are photoelectricconversion units of second type included in a third imaging element 343and in a second imaging element 341 that are imaging elements of secondtype, are stacked and formed in a semiconductor substrate 370. Inaddition, a first photoelectric conversion unit 310A that is aphotoelectric conversion unit of first type is arranged on an upper sideof the semiconductor substrate 370 (specifically, upper side of secondimaging element 341). Here, the first photoelectric conversion unit 310Aincludes a first electrode 321, a photoelectric conversion layer 323including an organic material, and a second electrode 322. The firstphotoelectric conversion unit 310A is included in a first imagingelement 310 that is an imaging element of first type. The secondphotoelectric conversion unit 341A and the third photoelectricconversion unit 343A photoelectrically convert, for example, blue lightand red light, respectively, based on the difference in absorptioncoefficients. In addition, the first photoelectric conversion unit 310Aphotoelectrically converts, for example, green light.

The charge generated by the photoelectric conversion in the secondphotoelectric conversion unit 341A and the third photoelectricconversion unit 343A is temporarily stored in the second photoelectricconversion unit 341A and the third photoelectric conversion unit 343A.Subsequently, a vertical transistor (gate portion 345 is illustrated)and a transfer transistor (gate portion 346 is illustrated) transfer thecharge to a second floating diffusion layer (Floating Diffusion) FD₂ anda third floating diffusion layer FD₃, respectively. The charge isfurther output to an external reading circuit (not illustrated). Thetransistors and the floating diffusion layers FD₂ and FD₃ are alsoformed on the semiconductor substrate 370.

The charge generated by the photoelectric conversion in the firstphotoelectric conversion unit 310A is stored in a first floatingdiffusion layer FD₁ formed on the semiconductor substrate 370 through acontact hole portion 361 and a wiring layer 362. In addition, the firstphotoelectric conversion unit 310A is also connected to a gate portion352 of an amplification transistor that converts the charge amount intovoltage through the contact hole portion 361 and the wiring layer 362.Furthermore, the first floating diffusion layer FD₁ is part of a resettransistor (gate portion 351 is illustrated). Reference number 371denotes an element separation region. Reference number 372 denotes anoxide film formed on the surface of the semiconductor substrate 370.Reference numbers 376 and 381 denote interlayer insulating layers.Reference number 383 denotes an insulating layer. Reference number 314denotes an on-chip micro lens.

CITATION LIST Patent Literature

-   [PTL 1]

Japanese Patent Laid-Open No. 2016-63165

[PTL 2]

Japanese Patent Laid-Open No. 2011-138927

SUMMARY Technical Problems

However, in the technique disclosed in Japanese Patent Laid-Open No.2016-63165, there is a restriction that the storage electrode and thesecond insulating layer formed on the storage electrode need to beformed in the same length, and there are detailed regulations regardingthe interval between the storage electrode and the collection electrodeand the like. Therefore, the production process may become complicated,and the manufacturing yield may be reduced. Furthermore, although thereare some references regarding the materials included in thesemiconductor layer, more specific compositions and configurations ofthe materials are not mentioned. In addition, a correlation equation ofthe mobility of the semiconductor layer and the stored charge ismentioned. However, matters regarding improvement in the transfer ofcharge, such as a matter regarding the mobility of the semiconductorlayer and a matter regarding the relationship in energy level betweenthe semiconductor layer and the part of the photoelectric conversionlayer adjacent to the semiconductor layer, that are important intransferring the generated charge are not mentioned.

Therefore, an object of the present disclosure is to provide an imagingelement, a stacked imaging element, and a solid-state imaging apparatuswith excellent transfer characteristics of charge stored in aphotoelectric conversion layer in spite of simple configuration andstructure.

Solution to Problems

Imaging elements according to a first aspect, a second aspect, and athird aspect of the present disclosure for attaining the object include:

a photoelectric conversion unit including a first electrode, aphotoelectric conversion layer, and a second electrode that are stacked,in which

an inorganic oxide semiconductor material layer is formed between thefirst electrode and the photoelectric conversion layer. Furthermore, inthe imaging element according to the first aspect of the presentdisclosure, the inorganic oxide semiconductor material layer includes atleast two types of elements selected from the group consisting ofindium, tungsten, tin, and zinc. Furthermore, in the imaging elementaccording to the second aspect of the disclosure, a LUMO value E₁ of amaterial included in a part of the photoelectric conversion layerpositioned near the inorganic oxide semiconductor material layer and aLUMO value E₂ of a material included in the inorganic oxidesemiconductor material layer satisfy the following expression. Note thatthe values of the following expression may be zero or negative values.

E1−E2<0.2 eV

Furthermore, in the imaging element according to the third aspect of thedisclosure, the mobility of a material included in the inorganic oxidesemiconductor material layer is equal to or greater than 10 cm²/V·s.

A stacked imaging element of the present disclosure for attaining theobject includes at least one imaging element according to the first tothird aspects of the present disclosure.

A solid-state imaging apparatus according to a first aspect of thepresent disclosure for attaining the object includes a plurality ofimaging elements according to the first to third aspects of the presentdisclosure. In addition, a solid-state imaging apparatus according to asecond aspect of the present disclosure for attaining the objectincludes a plurality of stacked imaging elements of the presentdisclosure.

Note that in the following description, the imaging element according tothe first aspect of the present disclosure, the imaging elementaccording to the first aspect of the present disclosure included in thestacked imaging element of the present disclosure, the imaging elementaccording to the first aspect of the present disclosure included in thesolid-state imaging apparatuses according to the first and secondaspects of the present disclosure may be collectively referred to as“imaging element and the like according to the first aspect of thepresent disclosure.” In addition, the imaging element according to thesecond aspect of the present disclosure, the imaging element accordingto the second aspect of the present disclosure included in the stackedimaging element of the present disclosure, and the imaging elementaccording to the second aspect of the present disclosure included in thesolid-state imaging apparatuses according to the first and secondaspects of the present disclosure may be collectively referred to as“imaging element and the like according to the second aspect of thepresent disclosure.” Furthermore, the imaging element according to thethird aspect of the present disclosure, the imaging element according tothe third aspect of the present disclosure included in the stackedimaging element of the present disclosure, and the imaging elementaccording to the third aspect of the present disclosure included in thesolid-state imaging apparatuses according to the first and secondaspects of the present disclosure may be collectively referred to as“imaging element and the like according to the third aspect of thepresent disclosure.”

Advantageous Effects of Invention

In the imaging element and the like according to the first aspect of thepresent disclosure, the materials included in the inorganic oxidesemiconductor material layer are defined. Furthermore, in the imagingelement and the like according to the second aspect of the presentdisclosure, a predetermined relationship between the LUMO value E₁ ofthe material included in the part of the photoelectric conversion layerpositioned near the inorganic oxide semiconductor material layer and theLUMO value E₂ of the material included in the inorganic oxidesemiconductor material layer is defined. Furthermore, in the imagingelement and the like according to the third aspect of the presentdisclosure, the mobility of the material included in the inorganic oxidesemiconductor material layer is defined. Therefore, an imaging elementwith excellent transfer characteristics of charge stored in thephotoelectric conversion layer can be provided in spite of simpleconfiguration and structure. Furthermore, the imaging element and thelike according to the first to third aspects of the present disclosurehave a two-layer structure of the inorganic oxide semiconductor materiallayer and the photoelectric conversion layer, and this can preventrecombination during charge storage. The transfer efficiency of thecharge stored in the photoelectric conversion layer to the firstelectrode can be increased, and the generation of dark current can besuppressed. Note that the advantageous effects described in the presentspecification are illustrative only and are not limited. In addition,there may also be additional advantageous effects.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic partial cross-sectional view of an imaging elementof Embodiment 1.

FIG. 2 is an equivalent circuit diagram of the imaging element ofEmbodiment 1.

FIG. 3 is an equivalent circuit diagram of the imaging element ofEmbodiment 1.

FIG. 4 is a schematic layout drawing of a first electrode, a chargestorage electrode, and transistors of a control unit included in theimaging element of Embodiment 1.

FIG. 5 is a diagram schematically illustrating a state of potential ineach section during operation of the imaging element of Embodiment 1.

FIGS. 6A, 6B, and 6C are equivalent circuit diagrams of imaging elementsof Embodiments 1, Embodiment 4, and Embodiment 6 for describing eachsection of FIG. 5 (Embodiment 1), FIGS. 20 and 21 (Embodiment 4), andFIGS. 32 and 33 (Embodiment 6).

FIG. 7 is a schematic layout drawing of the first electrode and thecharge storage electrode included in the imaging element of Embodiment1.

FIG. 8 is a schematic perspective view of the first electrode, thecharge storage electrode, a second electrode, and a contact hole portionincluded in the imaging element of Embodiment 1.

FIG. 9 is an equivalent circuit diagram of a modified example of theimaging element of Embodiment 1.

FIG. 10 is a schematic layout drawing of the first electrode, the chargestorage electrode, and the transistors of the control unit included inthe modified example of the imaging element of Embodiment 1 illustratedin FIG. 9.

FIG. 11 is a schematic partial cross-sectional view of an imagingelement of Embodiment 2.

FIG. 12 is a schematic partial cross-sectional view of an imagingelement of Embodiment 3.

FIG. 13 is a schematic partial cross-sectional view of a modifiedexample of the imaging element of Embodiment 3.

FIG. 14 is a schematic partial cross-sectional view of another modifiedexample of the imaging element in Embodiment 3.

FIG. 15 is a schematic partial cross-sectional view of yet anothermodified example of the imaging element in Embodiment 3.

FIG. 16 is a schematic partial cross-sectional view of part of theimaging element of Embodiment 4.

FIG. 17 is an equivalent circuit diagram of the imaging element ofEmbodiment 4.

FIG. 18 is an equivalent circuit diagram of the imaging element ofEmbodiment 4.

FIG. 19 is a schematic layout drawing of the first electrode, a transfercontrol electrode, the charge storage electrode, and the transistors ofthe control unit included in the imaging element of Embodiment 4.

FIG. 20 is a diagram schematically illustrating a state of potential iseach section during operation of the imaging element of Embodiment 4.

FIG. 21 is a diagram schematically illustrating a state of potential ineach section during another operation of the imaging element ofEmbodiment 4.

FIG. 22 is a schematic layout drawing of the first electrode, thetransfer control electrode, and the charge storage electrode included inthe imaging element of Embodiment 4.

FIG. 23 is a schematic perspective view of the first electrode, thetransfer control electrode, the charge storage electrode, the secondelectrode, and the contact hole portion included in the imaging elementof Embodiment 4.

FIG. 24 is a schematic layout drawing of the first electrode, thetransfer control electrode, the charge storage electrode, and thetransistors of the control unit included is a modified example of theimaging element of Embodiment 4.

FIG. 25 is a schematic partial cross-sectional view of part of animaging element of Embodiment 5.

FIG. 26 is a schematic layout drawing of the first electrode, the chargestorage electrode, and a discharge electrode included in the imagingelement of Embodiment 5,

FIG. 27 is a schematic perspective view of the first electrode, thecharge storage electrode, the discharge electrode, the second electrode,and the contact hole portion included is the imaging element ofEmbodiment 5.

FIG. 28 is a schematic partial cross-sectional view of the imagingelement of Embodiment 6.

FIG. 29 is an equivalent circuit diagram of the imaging element ofEmbodiment 6.

FIG. 30 is an equivalent circuit diagram of the imaging element ofEmbodiment 6.

FIG. 31 is a schematic layout drawing of the first electrode, the chargestorage electrode, and the transistors of the control unit included inthe imaging element of Embodiment 6.

FIG. 32 is a diagram schematically illustrating a state of potential ineach section during operation of the imaging element of Embodiment 6.

FIG. 33 is a diagram schematically illustrating a state of potential ineach section during another operation (during transfer) of the imagingelement of Embodiment 6.

FIG. 34 is a schematic layout drawing of the first electrode and thecharge storage electrode included in the imaging element of Embodiment6.

FIG. 35 is a schematic perspective view of the first electrode, thecharge storage electrode, the second electrode, and the contact holeportion included in the imaging element of Embodiment 6.

FIG. 36 is a schematic layout drawing of the first electrode and thecharge storage electrode included in a modified example of the imagingelement of Embodiment 6.

FIG. 37 is a schematic partial cross-sectional view of an imagingelement of Embodiment 7.

FIG. 38 is an enlarged schematic partial cross-sectional view of astacked part of the charge storage electrode, a photoelectric conversionlayer, and the second electrode in the imaging element of Embodiment 7.

FIG. 39 is a schematic layout drawing of the first electrode, the chargestorage electrode, and the transistors of the control unit in a modifiedexample of the imaging element of Embodiment 7.

FIG. 40 is an enlarged schematic partial cross-sectional view of astacked part of the charge storage electrode, the photoelectricconversion layer, and the second electrode in an imaging element ofEmbodiment 8.

FIG. 41 is a schematic partial cross-sectional view of an imagingelement of Embodiment 9.

FIG. 42 is a schematic partial cross-sectional view of imaging elementsof Embodiment 10 and Embodiment 11.

FIGS. 43A and 43B are schematic plan views of charge storage electrodesegments in Embodiment 11.

FIGS. 44A and 44B are schematic plan views of the charge storageelectrode segments in Embodiment 11.

FIG. 45 is a schematic layout drawing of the first electrode, the chargestorage electrode, and the transistors of the control unit included inthe imaging element of Embodiment 11.

FIG. 46 is a schematic layout drawing of the first electrode and thecharge storage electrode included in a modified example of the imagingelement of Embodiment 11.

FIG. 47 is a schematic partial cross-sectional view of imaging elementsof Embodiment 12 and Embodiment 11.

FIGS. 48A and 48B are schematic plan views of charge storage electrodesegments in Embodiment 12.

FIG. 49 is a schematic plan view of the first electrodes and the chargestorage electrode segments in a solid-date imaging apparatus ofEmbodiment 13.

FIG. 50 is a schematic plan view of the first electrodes and the chargestorage electrode segments in a first modified example of thesolid-state imaging apparatus of Embodiment 13.

FIG. 51 is a schematic plan view of the first electrodes and the chargestorage electrode segments in a second modified example of thesolid-state imaging apparatus of Embodiment 13.

FIG. 52 is a schematic plan view of the first electrodes and the chargestorage electrode segments in a third modified example of thesolid-state imaging apparatus of Embodiment 13.

FIG. 53 is a schematic plan view of the first electrodes and the chargestorage electrode segments in a fourth modified example of thesolid-state imaging apparatus of Embodiment 13.

FIG. 54 is a schematic plan view of the first electrodes and the chargestorage electrode segments in a fifth modified example of thesolid-state imaging apparatus of Embodiment 13.

FIG. 55 is a schematic plan view of the first electrodes and the chargestorage electrode segments in a sixth modified example of thesolid-state imaging apparatus of Embodiment 13.

FIG. 56 is a schematic plan view of the first electrodes and the chargestorage electrode segments in a seventh modified example of thesolid-state imaging apparatus of Embodiment 13.

FIG. 57 is a schematic plan view of the first electrodes and the chargestorage electrode segments in an eighth modified example of thesolid-state imaging apparatus of Embodiment 13.

FIG. 58 is a schematic plan view of the first electrodes and the chargestorage electrode segments in a ninth modified example of thesolid-state imaging apparatus of Embodiment 13.

FIGS. 59A, 59B, and 59C are charts illustrating examples of reading anddriving is an imaging element block of Embodiment 13.

FIG. 60 is a schematic plan view of the first electrodes and the chargestorage electrode segments in a solid-state imaging apparatus ofEmbodiment 14.

FIG. 61 is a schematic plan view of the first electrodes and the chargestorage electrode segments in a modified example of the solid-stateimaging apparatus of Embodiment 14.

FIG. 62 is a schematic plan view of the first electrodes and the chargestorage electrode segments in the modified example of the solid-stateimaging apparatus of Embodiment 14.

FIG. 63 is a schematic plan view of the first electrodes and the chargestorage electrode segments in the modified example of the solid-stateimaging apparatus of Embodiment 14.

FIG. 64 is a schematic partial cross-sectional view of another modifiedexample of the imaging element in Embodiment 1.

FIG. 65 is a schematic partial cross-sectional view of yet anothermodified example of the imaging element in Embodiment 1.

FIGS. 66A, 66B, and 66C are enlarged schematic partial cross-sectionalviews of the part of the first electrode and the like in yet anothermodified example of the imaging element of Embodiment 1.

FIG. 67 is an enlarged schematic partial cross-sectional view of thepart of the discharge electrode and the like in another modified exampleof the imaging element of Embodiment 5.

FIG. 68 is a schematic partial cross-sectional view of yet anothermodified example of the imaging element in Embodiment 1.

FIG. 69 is a schematic partial cross-sectional view of yet anothermodified example of the imaging element in Embodiment 1.

FIG. 70 is a schematic partial cross-sectional view of yet anothermodified example of the imaging element in Embodiment 1.

FIG. 71 is a schematic partial cross-sectional view of another modifiedexample of the imaging element in Embodiment 4.

FIG. 72 is a schematic partial cross-sectional view of yet anothermodified example of the imaging element in Embodiment 1.

FIG. 73 is a schematic partial cross-sectional view of yet anothermodified example of the imaging element in Embodiment 4.

FIG. 74 is an enlarged schematic partial cross-sectional view of thestacked part of the charge storage electrode, the photoelectricconversion layer, and the second electrode in a modified example of theimaging element of Embodiment 7.

FIG. 75 is an enlarged schematic partial cross-sectional view of thestacked part of the charge storage electrode, the photoelectricconversion layer, and the second electrode in a modified example of theimaging element of Embodiment 8.

FIG. 76 is a graph illustrating evaluation results of transfercharacteristics in the imaging element of Embodiment 1.

FIG. 77 is a graph illustrating results of evaluation of influence ontransfer characteristics influenced by a LUMO value E₁ of thephotoelectric conversion layer and a LUMO value E₂ of the materialincluded in the inorganic oxide semiconductor material layer in theimaging element of Embodiment 1.

FIGS. 78A and 78B are graphs indicating evaluation results of darkcurrent characteristics and external quantum efficiency, respectively,evaluated by using evaluation samples and a comparison sample inEmbodiment 1.

FIG. 79 is a conceptual diagram of a solid-state imaging apparatus ofEmbodiment 1.

FIG. 80 is a conceptual diagram of an example in which the solid-stateimaging apparatus including the imaging element and the like of thepresent disclosure is used in an electronic device (camera).

FIG. 81 is a conceptual diagram of a stacked imaging element (stackedsolid-state imaging apparatus) in the past.

DESCRIPTION OF EMBODIMENTS

Hereinafter, the present disclosure will be described based onEmbodiments with reference to the drawings. However, the presentdisclosure is not limited to Embodiments, and various values andmaterials in Embodiments are illustrative. Note that the presentdisclosure will be described in the following order.

1. Description Regarding Imaging Elements According to First to ThirdAspects of Present Disclosure, Stacked imaging Element of PresentDisclosure, and Solid-State Imaging Apparatuses According to First andSecond Aspects of Present Disclosure in General

2. Embodiment 1 (Imaging Elements According to First to Third Aspects ofPresent Disclosure, Stacked imaging Element of Present Disclosure, andSolid-State Imaging Apparatus According to Second Aspect of PresentDisclosure)

3. Embodiment 2 (Modification of Embodiment 1)

4. Embodiment 3 (Modification of Embodiments 1 and 2 and Solid-Stateimaging Apparatus According to First Aspect of Present Disclosure)

5. Embodiment 4 (Modification of Embodiments 1 to 3 and imaging ElementIncluding Transfer Control Electrode)

6. Embodiment 5 (Modification of Embodiments 1 to 4 and imaging Elementincluding Discharge Electrode)

7. Embodiment 6 (Modification of Embodiments 1 to 5 and Imaging Elementincluding a Plurality of Charge Storage Electrode Segments)

8. Embodiment 7 (Imaging Elements of First and Sixth Configurations)

9. Embodiment 8 (Imaging Elements of Second and Sixth Configurations ofPresent Disclosure)

10. Embodiment 9 (Imaging Element of Third Configuration)

11. Embodiment 10 (Imaging Element of Fourth Configuration)

12. Embodiment 11 (Imaging Element of Fifth Configuration)

13. Embodiment 12 (Imaging Element of Sixth Configuration)

14. Embodiment 13 (Solid-State Imaging Apparatuses of First and SecondConfigurations)

15. Embodiment 14 (Modification of Embodiment 13) 16. Etc.

<Description Regarding imaging Elements According to First to ThirdAspects of Present Disclosure, Stacked Imaging Element of PresentDisclosure, and Solid-State Imaging Apparatuses According to First andSecond Aspects of Present Disclosure in General>

The imaging element and the like according to the second aspect of thepresent disclosure can be in a mode where the LUMO value E₁ of thematerial included in the part of the photoelectric conversion layerpositioned near the inorganic oxide semiconductor material layer and theLUMO value E₂ of the material included in the inorganic oxidesemiconductor material layer satisfy the following expression.

E1−E2<0.1 eV

Furthermore, the imaging element and the like according to the secondaspect of the present disclosure including the preferred mode can be ina mode where the mobility of the material included in the inorganicoxide semiconductor material layer and the like is equal to or greaterthan 10 cm²/V·s.

In the imaging element in the past illustrated in FIG. 81, the chargegenerated by the photoelectric conversion in the second photoelectricconversion unit 341A and the third photoelectric conversion unit 343A istemporarily stored in the second photoelectric conversion. unit 341A andthe third photoelectric conversion unit 343A. The charge is thentransferred to the second floating diffusion layer FD₂ and the thirdfloating diffusion layer FD₃. Therefore, the second photoelectricconversion unit 341A and the third photoelectric conversion unit 343Acan be fully depleted. However, the charge generated by thephotoelectric conversion in the first photoelectric conversion unit 310Ais directly stored in the first floating diffusion layer FD₁. Therefore,it is difficult to fully deplete the first photoelectric conversion unit310A. Consequently, this may degrade the random noise due to an increasein kTC noise, and the imaging quality may be reduced.

The imaging element and the like according to the first aspect of thepresent disclosure, the imaging element and the like according to thesecond aspect of the present disclosure including the preferred mode, orthe imaging element and the like according to the third aspect of thepresent disclosure can be in a mode where the photoelectric conversionunit further includes the insulating layer and the charge storageelectrode arranged apart from the first electrode and arranged to facethe inorganic oxide semiconductor material layer through the insulatinglayer.

In this way, the charge storage electrode arranged apart from the firstelectrode and arranged to face the inorganic oxide semiconductormaterial layer through the insulating layer is provided. Therefore, inthe photoelectric conversion unit after the light is applied to thephotoelectric conversion unit, the charge can be stored in the inorganicoxide semiconductor material layer (in the inorganic oxide semiconductormaterial layer and the photoelectric conversion layer depending on thecase). Therefore, the charge storage portion can be fully depleted todelete the charge at the start of exposure. This can suppress thephenomenon of reduction in imaging quality caused by the degradation ofrandom noise due to an increase in kTC noise. Note that in the followingdescription, the inorganic oxide semiconductor material or the inorganicoxide semiconductor material layer and the photoelectric conversionlayer may be collectively referred to as “inorganic oxide semiconductormaterial layer and the like.”

Furthermore, in the imaging element and the like according to the firstaspect of the present disclosure including the preferred mode, in theimaging element and the like according to the second aspect of thepresent disclosure including the preferred mode, or in the imagingelement and the like according to the third aspect of the presentdisclosure including the preferred mode, the inorganic oxidesemiconductor material layer may riot contain gallium atoms.

Alternatively, in the imaging element and the like according to thefirst aspect of the present disclosure including the preferred mode, inthe imaging element and the like according to the second aspect of thepresent disclosure including the preferred mode, or in the imagingelement and the like according to the third aspect of the presentdisclosure including the preferred mode, the inorganic oxidesemiconductor material layer can include indium-tungsten oxide (IWO)that is a material obtained by adding tungsten (W) to indium oxide,indium-tungsten-zinc oxide (IWZO) that is a material obtained by addingtungsten R) and zinc (Zn) to indium oxide, indium-tin-zinc oxide (ITZO)that is a material obtained by adding tin (Sn) and zinc (Zn) to indiumoxide, or zinc-tin oxide (ZTO). Note that in a case where the inorganicoxide semiconductor material layer includes zinc-tin oxide (ZTO), a verysmall amount of ZnO may be deposited when an annealing process isapplied to a ZTO film during the formation of the ZTO film. Even in sucha case, it will be stated that the inorganic oxide semiconductormaterial layer includes zinc-tin oxide (ZTO). Specifically, theinorganic oxide semiconductor material layer includes In-W oxide orincludes In-Sn oxide, In-Zn oxide, W-Sn oxide, W-Zn oxide, Sn-Zn oxide,In-W-Sn oxide, In-W-Zn In-Sn-Zn oxide, or In-W-Sn-Zn oxide. In IWO, itis preferable that the mass ratio of the tungsten oxide be 10 to 30% bymass, where the total mass of the indium oxide and the tungsten oxide is100% by mass. Furthermore, in IWZO, it is preferable that the mass ratioof the tungsten oxide be 2 to 15% by mass and the mass ratio of the Znoxide be 1 to 3% by mass, where the total mass of the indium oxide, thetungsten oxide, and the Zn oxide is 100% by mass. In addition, in ITZO,it is preferable that the mass ratio of the tungsten oxide be 3 to 10%by mass and the mass ratio of the tin. oxide be 10 to 17% by mass, wherethe total mass of the indium oxide, the Zn oxide, and the Sn oxide is100% by, mass. However, the values are not limited to these.

The inorganic oxide semiconductor material layer may have a single-layerconfiguration or a multi-layer configuration. In addition, the materialincluded in the inorganic oxide semiconductor material layer positionedon the upper side of the charge storage electrode and the materialincluded in the inorganic oxide semiconductor material layer positionedon the upper side of the first electrode may be different.

The inorganic oxide semiconductor material layer can be deposited basedon, for example, a sputtering method. Specifically, a parallel platesputtering apparatus or a DC magnetron sputtering apparatus can be usedas a sputtering apparatus. An argon (Ar) gas can be used as a processgas, and a desirable sintered body, such as an InZnO sintered body, anInWO sintered body, and a ZTO sintered body, can be used as the targetin the sputtering method.

Note that the oxygen gas introduction amount (oxygen gas partialpressure) in forming the inorganic oxide semiconductor material layerbased on the sputtering method can be controlled to control the energylevel of the inorganic oxide semiconductor material layer. Specifically,it is preferable that oxygen gas partial pressure<=(O₂ gaspressure)/(total pressure of Ar gas and O₂ gas)>be 0.005 to 0.02 informing the layer based on the sputtering method. Furthermore, theimaging element and the like of the present disclosure can be in a modewhere the content rate of oxygen in the inorganic oxide semiconductormaterial layer is lower than the oxygen content rate of stoichiometriccomposition. Here, the energy level of the inorganic oxide semiconductormaterial layer can be controlled based on the content rate of oxygen.The lower the content rate of oxygen with respect to the oxygen contentrate of stoichiometric composition, that is, the higher the oxygendeficiency, the deeper the energy level can be.

Alternatively, in the imaging element and the like according to thefirst aspect of the present disclosure including the preferred mode, inthe imaging element and the like according to the second aspect of thepresent disclosure including the preferred mode, or in the imagingelement and the like according to the third aspect of the presentdisclosure including the preferred mode, the inorganic oxidesemiconductor material layer can include indium-tungsten-zinc oxide(IWZO).

Alternatively, in the imaging element and the like according to thefirst aspect of the present disclosure including the preferred mode, inthe imaging element and the like according to the second aspect of thepresent disclosure including the preferred mode, or in the imagingelement and the like according to the third aspect of the presentdisclosure including the preferred mode, the inorganic oxidesemiconductor material layer can include indium-tungsten oxide (IWO).

In the imaging element and the like according to the first aspect of thepresent disclosure including various preferred modes and configurationsdescribed above, it is desirable that the LUMO value E₁ of the materialincluded in the part of the photoelectric conversion layer positionednear the inorganic oxide semiconductor material layer and the LUMO valueE₂ of the material included in the inorganic oxide semiconductormaterial layer satisfy

E1−E2<0.2 eV,

preferably,

E1−E2<0.1 eV.

Here, “the part of the photoelectric conversion layer positioned nearthe inorganic oxide semiconductor material layer” denotes a part of thephotoelectric conversion layer positioned in the region corresponding toequal to or smaller than 10% of the thickness of the photoelectricconversion layer (that is, region from 0% to 10% of the thickness of thephotoelectric conversion. layer) with respect to the interface betweenthe inorganic oxide semiconductor material layer and the photoelectricconversion layer. This similarly applies to the imaging elementaccording to the second aspect of the present disclosure. The LUMO valueE₁ of the material included in the part of the photoelectric conversionlayer positioned near the inorganic oxide semiconductor material layeris an average value at the part of the photoelectric conversion layerpositioned near the inorganic oxide semiconductor material layer, andthe LUMO value E₂ of the material included in the inorganic oxidesemiconductor material layer is an average value in the inorganic oxidesemiconductor material layer.

Furthermore, in the imaging element and the like according to the firstaspect of the present disclosure including various preferred modes andconfigurations described above, it is preferable that the mobility ofthe material included in the inorganic oxide semiconductor materiallayer be equal to or greater than. 10 cm²/V·s.

Furthermore, the imaging element and the like according to the first tothird aspects of the present disclosure including the preferred modesand configurations described above can be in a mode where the inorganicoxide semiconductor material layer is amorphous (for example, amorphousmaterial not locally including crystal structure). Whether or not theinorganic oxide semiconductor material layer is amorphous can bedetermined based on. X-ray diffraction analysis.

Furthermore, the imaging element and the like according to the first tothird aspects of the present disclosure including the preferred modesand configurations described above can be in a mode where the thicknessof the inorganic oxide semiconductor material layer is 1×10⁻⁸ m to1.5×10⁻⁷ m, preferably, 2×10⁻⁸ m to 1.0×10⁻⁷ m, more preferably, 3×10⁻⁸m to 1.0×10⁻⁷ m.

Furthermore, the imaging element and the like according to the first tothird aspects of the present disclosure including the preferred modesand configurations described above can be in a mode where

the light is incident from the second electrode,

surface roughness Ra of the inorganic oxide semiconductor material layerat the interface between the photoelectric conversion layer and theinorganic oxide semiconductor material layer is equal to or smaller than1.5 nm, and the value of a root mean square roughness Rq of theinorganic oxide semiconductor material layer is equal to or smaller than2.5 nm. The surface roughness Ra and the surface roughness Rq are basedon the provision of JIS B0601:2013. The smoothness of the inorganicoxide semiconductor material layer at the interface between thephotoelectric conversion layer and the inorganic oxide semiconductormaterial layer can suppress surface scattering reflection in theinorganic oxide semiconductor material layer, and the bright currentcharacteristics in the photoelectric conversion can be improved. Thesurface roughness Ra of the charge storage electrode can be equal to orsmaller than 1.5 nm, and the value of the root mean square roughness Rqof the charge storage electrode can be equal to or smaller than 2.5 nm.

The imaging element and the like according to the first to third aspectsof the present disclosure including the preferred modes andconfigurations described above may be referred to as “imaging elementand the like of the present disclosure” for convenience. The imagingelement that is the imaging element and the like according to the firstto third aspects of the present disclosure including the preferred modesand configurations described above and that includes the charge storageelectrode may be referred to as imaging element and the like includingthe charge storage electrode of the present disclosure” for convenience.

In the imaging element and the like including the charge storageelectrode of the present disclosure, it is preferable that the lighttransmittance of the inorganic oxide semiconductor material layer withrespect to the light at wavelengths of 400 to 660 nm be equal to orgreater than 65%. In addition, it is preferable that the lighttransmittance of the charge storage electrode with respect to the lightat wavelengths of 400 to 660 nm be also equal to or greater than 65%. Itis preferable that a sheet resistance value of the charge storageelectrode be 3×10 Ω/□ to 1×10³Ω/□.

The imaging element and the like including the charge storage electrodeof the present disclosure can further include

a semiconductor substrate, in which

the photoelectric conversion unit is arranged on the upper side of thesemiconductor substrate. Note that the first electrode, the chargestorage electrode, and the second electrode are connected to a drivecircuit described later.

The second electrode positioned on the light incident side may be sharedby a plurality of imaging elements. That is, the second electrode can bea so-called solid electrode. The photoelectric conversion layer may beshared by a plurality of imaging elements. That is, one photoelectricconversion layer may be formed for a plurality of imaging elements. Thephotoelectric conversion layer may be provided for each imaging element.Although it is preferable to provide the inorganic oxide semiconductormaterial layer for each imaging element, the inorganic oxidesemiconductor material layer may be shared by a plurality of imagingelements and the like depending on the case. That is, for example, acharge movement control electrode described later may be providedbetween as imaging element and the like and the imaging element and thelike to thereby form one inorganic oxide semiconductor material layerfor a plurality of imaging elements and the like.

Furthermore, the imaging element and the like including the chargestorage electrode of the present disclosure including various preferredmodes and configurations described above can be in a mode where thefirst electrode extends in an opening portion provided on the insulatinglayer, and the first electrode is connected to the inorganic oxidesemiconductor material layer. Alternatively, the imaging element and thelike can be in a mode where the inorganic oxide semiconductor materiallayer extends in an opening portion provided on the insulating layer,and the inorganic oxide semiconductor material layer is connected to thefirst electrode. In this case,

an edge portion of a top surface of the first electrode can be coveredby the insulating layer,

the first electrode can be exposed on a bottom surface of the openingportion, and

a side surface of the opening portion can be sloped to extend from afirst surface toward a second surface where the first surface is asurface of the insulating layer in contact with the top surface of thefirst electrode, and the second surface is a surface of the insulatinglayer in contact with the part of the inorganic oxide semiconductormaterial layer facing the charge storage electrode. Furthermore, theside surface of the opening portion sloped to extend from the firstsurface toward the second surface can be positioned on the chargestorage electrode side.

Furthermore, the imaging element and the like including the chargestorage electrode of the present disclosure including various preferredmodes and configurations described above can further include

a control unit provided on the semiconductor substrate and including adrive circuit, in which

the first electrode and the charge storage electrode are connected tothe drive circuit,

in a charge storage period, the drive circuit applies a potential V₁₁ tothe first electrode and applies a potential V₁₂ to the charge storageelectrode, and charge is stored in the inorganic oxide semiconductormaterial layer (or in the inorganic oxide semiconductor material layerand the photoelectric conversion layer), and

in a charge transfer period, the drive circuit applies a potential V₂₁to the first electrode and applies a potential V₂₂ to the charge storageelectrode, and the charge stored in the inorganic oxide semiconductormaterial layer (or in the inorganic oxide semiconductor material layerand the photoelectric conversion layer) is read out to the control unitthrough the first electrode. Here, the potential of the first electrodeis higher than the potential of the second electrode, and V₁₂≥V₁₁ andV₂₂<V₂₁ hold.

Furthermore, the imaging element and the like including the chargestorage electrode of the present disclosure including various preferredmodes and configurations described above can further include a transfercontrol electrode (charge transfer electrode) arranged between the firstelectrode and the charge storage electrode, arranged apart from thefirst electrode and the charge storage electrode, and arranged to facethe inorganic oxide semiconductor material layer through the insulatinglayer. The imaging element and the like including the charge storageelectrode of the present disclosure in such a mode will be referred toas “imaging element and the like including the transfer controlelectrode of the present disclosure” for convenience.

In addition, the imaging element and the like including the transfercontrol electrode of the present disclosure can further include

a control unit provided on the semiconductor substrate and including thedrive circuit, in which

the first electrode, the charge storage electrode, and the transfercontrol circuit are connected to the drive circuit,

in the charge storage period, the drive circuit applies the potentialV₁₁ to the first electrode, applies the potential V₁₂ to the chargestorage electrode, and applies a potential V₁₃ to the transfer controlelectrode, and charge is stored in the inorganic oxide semiconductormaterial layer (or in the inorganic oxide semiconductor material layerand the photoelectric conversion layer), and

in the charge transfer period, the drive circuit applies the potentialV₂₁ to the first electrode, applies the potential V₂₂ to the chargestorage electrode, and applies a potential V₂₃ to the transfer controlelectrode, and the charge stored in the inorganic oxide semiconductormaterial layer (or in the inorganic oxide semiconductor material layerand the photoelectric conversion layer)) is read out to the control unitthrough the first electrode. Here, the potential of the first electrodeis higher than the potential of the second electrode, and V₁₂>V₁₃ andV₂₂≤V₂₁ hold.

Furthermore, the imaging element and the like including the chargestorage electrode of the present disclosure including various preferredmodes and configurations described above can further include a dischargeelectrode connected to the inorganic oxide semiconductor material layerand arranged apart from the first electrode and the charge storageelectrode. The imaging element and the like including the charge storageelectrode of the present disclosure in such a mode will be referred toas “imaging element and the like including the discharge electrode ofthe present disclosure” for convenience. In addition, the imagingelement and the like including the discharge electrode of the presentdisclosure can be in a mode where the discharge electrode is arranged tosurround the first electrode and the charge storage electrode (that is,in a frame shape). The discharge electrode can be shared (standardized)by a plurality of imaging elements. Furthermore, in this case,

the inorganic oxide semiconductor material layer can extend in a secondopening portion provided on the insulating layer and can be connected tothe discharge electrode,

an edge portion of a top surface of the discharge electrode can becovered by the insulating layer,

the discharge electrode can be exposed on a bottom surface of the secondopening portion, and

a side surface of the second opening portion can be sloped to extendfrom a third surface toward a second surface, where the third surface isa surface of the insulating layer in contact with the top surface of thedischarge electrode, and the second surface is a surface of theinsulating layer in contact with the part of the inorganic oxidesemiconductor material layer facing the charge storage electrode.

Furthermore, the imaging element and the like including the dischargeelectrode of the present disclosure can further include

a control unit provided on the semiconductor substrate and including thedrive circuit, in which

the first electrode, the charge storage electrode, and the dischargeelectrode are connected to the drive circuit,

in the charge storage period, the drive circuit applies the potentialV₁₁ to the first electrode, applies the potential V₁₂ to the chargestorage electrode, and applies a potential V₁₄ to the dischargeelectrode, and charge is stored in the inorganic oxide semiconductormaterial layer (or in the inorganic oxide semiconductor material layerand the photoelectric conversion layer), and

in the charge transfer period, the drive circuit applies the potentialV₂₁ to the first electrode, applies the potential V₂₂ to the chargestorage electrode, and applies a potential V₂₄ to the dischargeelectrode, and the charge stored in the inorganic oxide semiconductormaterial layer (or in the inorganic oxide semiconductor material layerand the photoelectric conversion layer) is read out to the control unitthrough the first electrode. Here, the potential of the first electrodeis higher than the potential of the second electrode, and V₁₄>V₁₁ andV₂₄<V₂₁ hold.

Furthermore, in various preferred modes and configurations describedabove regarding the imaging element and the like including the chargestorage electrode of the present disclosure, the charge storageelectrode can include a plurality of charge storage electrode segments.The imaging element and the like including the charge storage electrodeof the present disclosure in such as a mode will be referred to as“imaging element and the like including a plurality of charge storageelectrode segments of the present disclosure” for convenience. Thenumber of charge storage electrode segments can be two or more.Furthermore, there are cases where different potentials are applied to Ncharge storage electrode segments in the imaging element and the likeincluding the plurality of charge storage electrode segments of thepresent disclosure.

In a case where the potential of the first electrode is higher than thepotential of the second electrode, the potential applied to a chargestorage electrode segment (first photoelectric conversion unit segment)positioned at a place closest to the first electrode can be higher thanthe potential applied to a charge storage electrode segment (Nthphotoelectric conversion unit segment) positioned at a place farthestfrom the first electrode in the charge transfer period, and

in a case where the potential of the first electrode is lower than thepotential of the second electrode, the potential applied to the chargestorage electrode segment (first photoelectric conversion unit segment)positioned at the place closest to the first electrode can be lower thanthe potential applied to the charge storage electrode segment (Nthphotoelectric conversion unit segment) positioned at the place farthestfrom the first electrode in the charge transfer period.

In the imaging element and the like including the charge storageelectrode of the present disclosure including various preferred modesand configurations described above,

at least a floating diffusion layer and an amplification transistorincluded in the control unit can be provided on the semiconductorsubstrate, and

the first electrode can be connected to the floating diffusion layer anda gate portion of the amplification transistor. In addition, in thiscase, furthermore,

a reset transistor and a selection transistor included in the controlunit can be further provided on the semiconductor substrate,

the floating diffusion layer can be connected to one source/drain regionof the reset transistor,

one source/drain region of the amplification transistor can be connectedto one source/drain region of the selection transistor, and anothersource/drain region of the selection transistor can be connected to asignal line.

Furthermore, the imaging element and the like including the chargestorage electrode of the present disclosure including various preferredmodes and configurations described above can be in a mode where the sizeof the charge storage electrode is larger than the first electrode.Although not limited, it is preferable to satisfy

4≤S₁′/S₁,

where S₁′ is the area of the charge storage electrode, and S₁ is thearea of the first electrode.

Alternatively, examples of modified examples of the imaging element andthe like of the present disclosure including various preferred modesdescribed above include imaging elements of first to sixthconfigurations described below. That is, in the imaging elements of thefirst to sixth configurations in the imaging element and the like of thepresent disclosure including various preferred modes described above,

the photoelectric conversion unit includes N (where N≥2) photoelectricconversion unit segments,

the inorganic oxide semiconductor material layer and the photoelectricconversion layer include N photoelectric conversion layer segments,

the insulating layer includes N insulating layer segments,

the charge storage electrode includes N charge storage electrodesegments in the imaging elements of the first to third configurations,

the charge storage electrode includes N charge storage electrodesegments arranged apart from each other in the imaging elements of thefourth and fifth configurations,

an nth (where n=1, 2, 3, N) photoelectric conversion unit segmentincludes an nth charge storage electrode segment, an nth insulatinglayer segment, and an nth photoelectric conversion layer segment, and.

the larger the value of n of the photoelectric conversion unit segment,the farther the position of the photoelectric conversion unit segmentfrom the first electrode. Here, the “photoelectric conversion layersegment” denotes a segment including the photoelectric conversion layerand the inorganic oxide semiconductor material layer that are stacked.

Furthermore, in the imaging element of the first configuration, thethicknesses of the insulating layer segments gradually change from thefirst photoelectric conversion unit segment to the Nth photoelectricconversion unit segment. In addition, in the imaging element of thesecond configuration, the thicknesses of the photoelectric conversionlayer segments gradually change from the first photoelectric conversionunit segment to the Nth photoelectric conversion unit segment. Note thatin the photoelectric conversion layer segment, the thickness of the partof the photoelectric conversion layer may be changed, and the thicknessof the part of the inorganic oxide semiconductor material layer may bemaintained to change the thickness of the photoelectric conversion layersegment. The thickness of the part of the photoelectric conversion layermay be maintained, and the thickness of the part of the inorganic oxidesemiconductor material layer may be changed to change the thickness ofthe photoelectric conversion layer segment. The thickness of the part ofthe photoelectric conversion layer may be changed, and the thickness ofthe part of the inorganic oxide semiconductor material layer may bechanged to change the thickness of the photoelectric conversion layersegment. Furthermore, in the imaging element of the third configuration,the materials included in the insulating layer segments vary betweenadjacent photoelectric conversion unit segments. In addition, in theimaging element of the fourth configuration, the materials included inthe charge storage electrode segments vary between adjacentphotoelectric conversion unit segments. Furthermore, in the imagingelement of the fifth configuration, the areas of the charge storageelectrode segments gradually decrease from the first photoelectricconversion unit segment to the Nth photoelectric conversion unitsegment. The areas may be continuously decrease or may decreasestep-wise.

Alternatively, in the imaging element of the sixth configuration in theimaging element and the like of the present disclosure including variouspreferred modes described above, the cross-sectional area of the stackedpart of the charge storage electrode, the insulating layer, theinorganic oxide semiconductor material layer, and the photoelectricconversion layer when the stacked part is cut in a YZ virtual planechanges in accordance with the distance from the first electrode, wherethe Z direction is a stacking direction of the charge storage electrode,the insulating layer, the inorganic oxide semiconductor material layer,and the photoelectric conversion layer, and the X direction is adirection away from the first electrode. The change in thecross-sectional area may be continuous change or may be step-wisechange.

In the imaging elements of the first and second configurations, the Nphotoelectric conversion layer segments are continuously provided. The Ninsulating layer segments are also continuously provided, and the Ncharge storage electrode segments are also continuously provided. In theimaging elements of the third to fifth configurations, the Nphotoelectric conversion layer segments are continuously provided.Furthermore, in the imaging elements of the fourth and fifthconfigurations, the N insulating layer segments are continuouslyprovided.

On the other hand, in the imaging element of the third configuration,the N insulating layer segments are provided to correspond to thephotoelectric conversion unit segments, respectively. Furthermore, inthe imaging elements of the fourth and fifth configurations and in theimaging element of the third configuration depending on the case, the Ncharge storage electrode segments are provided to correspond to thephotoelectric conversion unit segments, respectively. Furthermore, inthe imaging elements of the first to sixth configurations, the samepotential is applied to all of the charge storage electrode segments.Alternatively, in the imaging elements of the fourth and fifthconfigurations and in the imaging element of the third configurationdepending on the case, different potentials may be applied to the Ncharge storage electrode segments.

In the imaging element and the like of the present disclosure includingthe imaging elements of the first to sixth configurations, thethicknesses of the insulating layer segments are defined. Alternatively,the thicknesses of the photoelectric conversion layer segments aredefined. Alternatively, the materials included in the insulating layersegments are different. Alternatively, the materials included in thecharge storage electrode segments are different. Alternatively, theareas of the charge storage electrode segments are defined.Alternatively, the cross-sectional areas of the stacked parts aredefined. Therefore, a kind of charge transfer gradient is formed, andthe charge generated by the photoelectric conversion can be more easilyand certainly transferred to the first electrode. In addition, as aresult, generation of residual image or transfer leftover can beprevented.

In the imaging elements of the first to fifth configurations, the largerthe value of n of the photoelectric conversion unit segment, the fartherthe position of the photoelectric conversion unit segment from the firstelectrode. Whether or not the photoelectric conversion unit segment ispositioned away from the first electrode is determined on the basis of Xdirection. In addition, the direction away from the first electrode isthe X direction in the imaging element of the sixth configuration, andthe “X direction” is defined as follows. That is, the pixel regionincluding a plurality of arrayed imaging elements or stacked imagingelements includes a plurality of pixels arranged in a two-dimensionalarray, that is, systematically arranged in the X direction and the Ydirection. In a case where the plane shape of the pixels is rectangle,the extending direction of the side closest to the first electrode isthe I direction, and the direction orthogonal to the Y direction is theX direction. Alternatively, in a case where the plane shape of thepixels is an arbitrary shape, the overall direction including the linesegment or curve closest to the first electrode is the Y direction, andthe direction orthogonal to the Y direction is the X direction.

Hereinafter, a case where the potential of the first electrode is higherthan the potential of the second electrode will be described regardingthe imaging elements of the first to sixth configurations.

In the imaging element of the first configuration, the thicknesses ofthe insulating layer segments gradually change from the firstphotoelectric conversion unit segment to the Nth photoelectricconversion unit segment. It is preferable that the thicknesses of theinsulating layer segments gradually increase, and as a result, a kind ofcharge transfer gradient is formed. Furthermore, when the state shiftsto |V₁₂|≥|V₁₁| in the charge storage period, the nth photoelectricconversion unit segment can store more charge than the (n+1)thphotoelectric conversion unit segment, and a strong electric field isapplied. This can certainly prevent the flow of charge from the firstphotoelectric conversion unit segment to the first electrode. Inaddition, when the state shifts to |V₂₂|<|V₂₁| in the charge transferperiod, the flow of charge from the first photoelectric conversion unitsegment to the first electrode and the flow of charge from the (n+1)thphotoelectric conversion unit segment to the nth photoelectricconversion unit segment can be certainly secured.

In the imaging element of the second configuration, the thicknesses ofthe photoelectric conversion layer segments gradually change from thefirst photoelectric conversion unit segment to the Nth photoelectricconversion unit segment. It is preferable that the thicknesses of thephotoelectric conversion layer segments gradually increase, and as aresult, a kind of charge transfer gradient is formed. Furthermore, whenthe state shifts to V₁₂≥V₁₁ in the charge storage period, a strongerelectric field is applied to the nth photoelectric conversion unitsegment than to the (n+1)th photoelectric conversion unit segment. Thiscan certainly prevent the flow of charge from the first photoelectricconversion unit segment to the first electrode.

Furthermore, when the state shifts to V₂₂<V₂₁ in the charge transferperiod, the flow of charge from the first photoelectric conversion unitsegment to the first electrode and the flow of charge from the (n+1)thphotoelectric conversion unit segment to the nth photoelectricconversion unit segment can be certainly secured.

In the imaging element of the third configuration, the materialsincluded in the insulating layer segments vary between adjacentphotoelectric conversion unit segments. As a result, a kind of chargetransfer gradient is formed. It is preferable that the values ofdielectric constant of the materials included in the insulating layersegments gradually decrease from the first photoelectric conversion unitsegment to the Nth photoelectric conversion unit segment. In addition,when the state shifts to V₁₂≥V₁₁ in the charge storage period byadopting the configuration, the nth photoelectric conversion unitsegment can store more charge than the (n+1)th photoelectric conversionunit segment. Furthermore, when the state shifts to V₂₂<V₂₁ in thecharge transfer period, the flow of charge from the first photoelectricconversion unit segment to the first electrode and the flow of chargefrom the (n+1)th photoelectric conversion unit segment to the nthphotoelectric conversion unit segment can be certainly secured.

In the imaging element of the fourth configuration, the materialsincluded in the charge storage electrode segments vary between adjacentphotoelectric conversion unit segments. As a result, a kind of chargetransfer gradient is formed. It is preferable that the values of workfunction of the materials included in the insulating layer segmentsgradually increase from the first photoelectric conversion unit segmentto the Nth photoelectric conversion unit segment. In addition, byadopting the configuration, a potential gradient advantageous for thesignal charge transfer can be formed regardless of whether the voltageis positive or negative.

In the imaging element of the fifth configuration, the areas of thecharge storage electrode segments gradually decrease from the firstphotoelectric conversion unit segment to the Nth photoelectricconversion unit segment. As a result, a kind of charge transfer gradientis formed. Therefore, when the state shifts to V₁₂≥V₁₁ in the chargestorage period, the nth photoelectric conversion unit segment can storemore charge than the (n+1)th photoelectric conversion unit segment.Furthermore, when the state shifts to V₂₂<V₂₁ in the charge transferperiod, the flow of charge from the first photoelectric conversion unitsegment to the first electrode and the flow of charge from the (n+1)thphotoelectric conversion unit segment to the nth photoelectricconversion unit segment can be certainly secured.

In the imaging element of the sixth configuration, the cross-sectionalareas of the stacked parts change in accordance with the distance fromthe first electrode. As a result, a kind of charge transfer gradient, isformed. Specifically, the thicknesses of the cross sections of thestacked parts can be constant, and the widths of the cross sections ofthe stacked parts can decrease with an increase in the distance from thefirst electrode. By adopting the configuration, a region near the firstelectrode can store more charge than a far region when the state shiftsto V₁₂≥V₁₁ in the charge storage period as described in the imagingelement of the fifth configuration. Therefore, when the state shifts toV₂₂<V₂₁ in the charge transfer period, the flow of charge from theregion near the first electrode to the first electrode and the flow ofcharge from the far region to the near region can be certainly secured.On the other hand, the widths of the cross sections of the stacked partscan be constant, and the thicknesses of the cross sections of thestacked parts, specifically, the thicknesses of the insulating layersegments, can be gradually increased. By adopting the configuration, aregion near the first electrode can store more charge than a far regionwhen the state shifts to V₁₂≥V₁₁ in the charge storage period asdescribed in the imaging element of the first configuration. Inaddition, a strong electric field is applied, and this can certainlyprevent the flow of charge from the region near the first electrode tothe first electrode. Furthermore, when the state shifts to V₂₂<V₂₁ inthe charge transfer period, the flow of charge from the region near thefirst electrode to the first electrode and the flow of charge from thefar region to the near region can be certainly secured. In addition, byadopting the configuration of gradually increasing the thicknesses ofthe photoelectric conversion layer segments, a stronger electric fieldis applied to the region near the first electrode than to the far regionwhen the state shifts to V₁₂≥V₁₁ in the charge storage period, and theflow of charge from the region near the first electrode to the firstelectrode can be certainly prevented as described in the imaging elementof the second configuration. Furthermore, when the state shifts toV₂₂<V₂₁ in the charge transfer period, the flow of charge from theregion near the first electrode to the first electrode and the flow ofcharge from the far region to the near region can be certainly secured.

A solid-state imaging apparatus as a modified example of the solid-stateimaging apparatus according to the first and second aspects of thepresent disclosure can include

a plurality of imaging elements of the first to sixth configurations, inwhich

the plurality of imaging elements are included in an imaging elementblock, and

the first electrode is shared by the plurality of imaging elementsincluded in the imaging element block. The solid-state imaging apparatusconfigured in this way will be referred to as a “solid-state imagingapparatus of first configuration” for convenience. Alternatively, asolid-state imaging apparatus as a modification of the solid-stateimaging apparatus according to the first and second aspects of thepresent disclosure can include

a plurality of imaging elements of the first to sixth configurations ora plurality of stacked imaging elements including at least one imagingelement of the first to sixth configurations, in which

the plurality of imaging elements or stacked imaging elements areincluded in an imaging element block, and

the first electrode is shared by the plurality of imaging elements or stacked imaging elements included in the imaging element block. Thesolid-state imaging apparatus configured in this way will be referred toas a “solid-state imaging apparatus of second configuration” forconvenience. In addition, the first electrode can be shared by theplurality of imaging elements included in the imaging element block tosimplify and miniaturize the configuration and the structure in thepixel region including a plurality of arrayed imaging elements.

In the solid-state imaging apparatuses of the first and secondconfigurations, one floating diffusion layer is provided for a pluralityof imaging elements (one imaging element block). Here, the plurality ofimaging elements provided for one floating diffusion layer may include aplurality of imaging elements of first type described later or mayinclude at least one imaging element of first type and one or two ormore imaging elements of second type described later. In addition, thetiming of the charge transfer period can be appropriately controlled toallow the plurality of imaging elements to share one floating diffusionlayer. The plurality of imaging elements operate together and areconnected as an imaging element block to a drive circuit describedlater. That is, the plurality of imaging elements included in theimaging element block are connected to one drive circuit. However, thecharge storage electrode is controlled for each imaging element. Inaddition, the plurality of imaging elements can share one contact holeportion. As for the arrangement relationship between the first electrodeshared by the plurality of imaging elements and the charge storageelectrode of each imaging element, the first electrode may be arrangedadjacent to the charge storage electrode of each imaging element.Alternatively, the first electrode may be arranged adjacent to thecharge storage electrodes of part of the plurality of imaging elementsand not arranged adjacent to the charge storage electrodes of the restof the plurality of imaging elements. In this case, the movement ofcharge from the rest of the plurality of imaging elements to the firstelectrode is movement through part of the plurality of imaging elements.It is preferable that the distance between the charge storage electrodeincluded in the imaging element and the charge storage electrodeincluded in the imaging element (referred to as “distance A” forconvenience) be longer than the distance between the first electrode andthe charge storage electrode in the imaging element adjacent to thefirst electrode (referred to as “distance B” for convenience) in orderto certainly move the charge from each imaging element to the firstelectrode. In addition, it is preferable that the farther the positionof the imaging element from the first electrode, the larger the value ofthe distance A.

Furthermore, the imaging element and the like of the present disclosureincluding various preferred modes and configurations described above canbe in a mode where the light is incident from the second electrode side,and a light shielding layer is formed on the light incident side closerto the second electrode. Alternatively, the light may be incident fromthe second electrode side, and the light may not be incident on thefirst electrode (first electrode and transfer control electrodedepending on the case). Furthermore, in this case, the light shieldinglayer can be formed on the light incident side closer to the secondelectrode and on the upper side of the first electrode (first electrodeand transfer control electrode depending on the case). Alternatively, anon-chip micro lens can be provided on the upper side of the chargestorage electrode and the second electrode, and the light incident onthe on-chip micro lens can be collected by the charge storage electrode.Here, the light shielding layer may be arranged on the upper side of thesurface on the light incident side of the second electrode or may bearranged on the surface on the light incident side of the secondelectrode. The light shielding layer may be formed on the secondelectrode depending on the case. Examples of the materials included inthe light shielding layer include chromium (Cr), copper (Cu), aluminum(Al), tungsten (W), and a light-proof resin (for example, polyimideresin).

Specific examples of the imaging element and the like of the presentdisclosure include: an imaging element (referred to as “blue lightimaging element of first type” for convenience) sensitive to blue lightincluding a photoelectric conversion layer or a photoelectric conversionunit (referred to as “blue light photoelectric conversion layer of firsttype” or “blue light photoelectric conversion unit of first type” forconvenience) that absorbs blue light (light at 425 to 495 nm); animaging element (referred to as “green light imaging element of firsttype” for convenience) sensitive to green light including aphotoelectric conversion layer or a photoelectric conversion unit(“referred to as green light photoelectric conversion layer of firsttype” or “green light photoelectric conversion unite, of first type” forconvenience) that absorbs green light (light at 495 to 570 nm); and animaging element (referred to as “red light imaging element of firsttype” for convenience) sensitive to red light including a photoelectricconversion layer or a photoelectric conversion unit (referred to as “redlight photoelectric conversion layer of first type” or “red lightphotoelectric conversion unit of first type” for convenience) thatabsorbs red light (light at 620 to 750 nm). In addition, an imagingelement sensitive to blue light that is an element in the past notincluding the charge storage electrode will be referred to as a “bluelight imaging element of second type” for convenience. An imagingelement in the past sensitive to green light will be referred to as a“green light imaging element of second type” for convenience An imagingelement in the past sensitive to red light will be referred to as a “redlight imaging element of second type” for convenience. A photoelectricconversion layer or a photoelectric conversion unit included in the bluelight imaging element of second type will be referred to as a “bluelight photoelectric conversion layer of second type” or a “blue lightphotoelectric conversion unit of second type” for convenience. Aphotoelectric conversion layer or a photoelectric conversion unitincluded in the green light imaging element of second type will bereferred to as a “green light photoelectric conversion layer of secondtype” or a “green light photoelectric conversion unit of second type”for convenience. A photoelectric conversion layer or a photoelectricconversion unit included in the red light imaging element of second typewill be referred to as a “red light photoelectric conversion layer ofsecond type” or a “red light photoelectric conversion unit of secondtype” for convenience.

Specific examples of the configuration and the structure of the stackedimaging element including the charge storage electrode include:

[A] a configuration and a structure in which the blue lightphotoelectric conversion unit of first type, the green lightphotoelectric conversion unit of first type, and the red lightphotoelectric conversion unit of first type are stacked in the verticaldirection, and

control units of the blue light imaging element of first type, the greenlight imaging element of first type, and the red light imaging elementof first type are provided on the semiconductor substrate;

[B] a configuration and a structure in which the blue lightphotoelectric conversion unit of first type and the green lightphotoelectric conversion unit of first type are stacked in the verticaldirection,

the red light photoelectric conversion unit of second type is arrangedon the lower side of these two layers of photoelectric conversion unitsof first type, and

control units of the blue light imaging element of first type, the greenlight imaging element of first type, and the red light imaging elementof second type are provided on the semiconductor substrate;

[C] a configuration and a structure in which the blue lightphotoelectric conversion unit of second type and the red lightphotoelectric conversion unit of second type are arranged on the lowerside of the green light photoelectric conversion unit of first type, and

control units of the green light imaging element of first type, the bluelight imaging element of second type, and the red light imaging elementof second type are provided on the semiconductor substrate; and

[D] a configuration and a structure in which the green lightphotoelectric conversion unit of second type and the red lightphotoelectric conversion unit of second type are arranged on the lowerside of the blue light photoelectric conversion unit of first type, and

control units of the blue light imaging element of first type, the greenlight imaging element of second type, and the red light imaging elementof second type are provided on the semiconductor substrate. It ispreferable that the arrangement order of the photoelectric conversionunits of the imaging elements in the vertical direction be the bluelight photoelectric conversion unit, the green light photoelectricconversion unit, and the red light photoelectric conversion unit fromthe light incident direction or the green light photoelectric conversionunit, the blue light photoelectric conversion unit, and the red lightphotoelectric conversion unit from the light incident direction. This isbecause the light at a shorter wavelength is efficiently absorbed on theincident surface side. Red has the longest wavelength among the threecolors, and it is preferable to position the red light photoelectricconversion unit in the lowest layer as viewed from the light incidentsurface. The stacked structure of the imaging elements provide onepixel. In addition, a near-infrared photoelectric conversion unit (orinfrared photoelectric conversion unit) of first type may be included.Here, it is preferable that the photoelectric conversion layer of theinfrared photoelectric conversion unit of first type include, forexample, organic materials and be arranged in the lowest layer of thestacked structure of the imaging elements of first type, above theimaging element of second type. Alternatively, a near-infraredphotoelectric conversion unit of second type (or infrared photoelectricconversion unit) may be included on the lower side of the photoelectricconversion units of first type.

In the imaging element of first type, the first electrode is formed on,for example, an interlayer insulating layer provided on thesemiconductor substrate. The imaging element formed on the semiconductorsubstrate can be a back illuminated type or a front illuminated type.

In a case where the photoelectric conversion layer includes organicmaterials, the photoelectric conversion layer can be in one of thefollowing four modes.

(1) The photoelectric conversion layer includes a p-type organicsemiconductor.

(2) The photoelectric conversion layer includes a n-type organicsemiconductor.

(3) The photoelectric conversion layer includes a stacked structure ofp-type organic semiconductor layer/n-type organic semiconductor layer.The photoelectric conversion layer includes a stacked structure ofp-type organic semiconductor layer/mixed layer (bulk hetero structure)of p-type organic semiconductor and n-type organic semiconductor/n-typeorganic semiconductor layer. The photoelectric conversion layer includesa stacked structure of p-type organic semiconductor layer/mixed layer(bulk hetero structure) of p-type organic semiconductor and n-typeorganic semiconductor. The photoelectric conversion layer includes astacked structure of n-type organic semiconductor/mixed layer (bulkhetero structure) of p-type organic semiconductor and n-type organicsemiconductor.

(4) The photoelectric conversion layer includes a mixture (bulk heterostructure) of p-type organic semiconductor and n-type organicsemiconductor.

Here, the order of stacking can be arbitrarily switched.

Examples of the p-type organic semiconductor include a naphthalenederivative, an anthracene derivative, a phenanthrene derivative, apyrene derivative, a perylene derivative, a tetracene derivative, apentacene derivative, a quinacridone derivative, a thiophene derivative,a thienothiophene derivative, a benzothiophene derivative, abenzothienobenzothiophene derivative, a triallylamine derivative, acarbazole derivative, a perylene derivative, a picene derivative, achrysene derivative, a fluoranthene derivative, a phthalocyaninederivative, a subphthalocyanine derivative, a subporphyrazinederivative, a metal complex including heterocyclic compounds as ligands,a polythiophene derivative, a polybenzothiadiazole derivative, and apolyfluorene derivative. Examples of the n-type organic semiconductorinclude a fullerene and a fullerene derivative <for example, fullerene(higher fullerene), such as C60, C70, and C74, endohedral fullerene, orthe like) or fullerene derivative (for example, fullerene fluoride, PCBMfullerene compound, fullerene multimer, or the like)>, an organicsemiconductor with larger (deeper) HOMO and LUMO than the p-type organicsemiconductor, and transparent inorganic metal oxide. Specific examplesof the n-type organic semiconductor include organic molecules including,as part of molecular framework, a heterocyclic compound containingnitrogen atoms, oxygen atoms, and sulfur atoms, such as a pyridinederivative, a pyrazine derivative, a pyrimidine derivative, a triazinederivative, a quinoline derivative, a quinoxaline derivative, anisoquinoline derivative, an acridine derivative, a phenazine derivative,a phenanthroline derivative, a tetrazole derivative, a pyrazolederivative, an imidazole derivative, a thiazole derivative, an oxazolederivative, an imidazole derivative, a benzimidazole derivative, abenzotriazole derivative, a benzoxazole derivative, a carbazolederivative, a benzofuran derivative, a dibenzofuran derivative, asubporphyrazine derivative, a polyphenyiene vinylene derivative, apolybenzothiadiazole derivative, and a polyfluorene derivative, anorganic metal complex, and a subphthalocyanine derivative. Examples ofgroups and the like included in the fullerene derivative include:halogen atoms; a straight-chain, branched, or cyclic alkyl group orphenyl group; a group including a straight-chain or condensed aromaticcompound; a group including halide; a partial fluoroalkyl group; aperfluoroalkyl group; a silylalkyl group; a silylalkoxy group; anarylsilyl group; an arylsulfanyl group; an alkylsulfanyl group; anarylsulfonyl group; an alkylsulfonyl group; an arylsulfide group; analkylsulfide group; an amino group; an alkylamino group; an acylaminogroup; a hydroxy group; an alkoxy group; an acylamino group; an acyloxygroup; a carbonyl group; a carboxy group; a carboxamide group; acarboalkoxy group; an acyl group; a sulfonyl group; a cyano group; anitro group; a group including chalcogenide; a phosphine group; aphosphon group; and derivatives of these. Although the thickness of thephotoelectric conversion layer including the organic materials (referredto as “organic photoelectric conversion layer” in some cases) is notlimited, the thickness can be, for example, 1×⁻⁸ m to 5×10⁻⁷ m,preferably, 2.5×10⁻⁸ m to 3×10⁻⁷ m, more preferably, 2.5×10⁻⁸ m to2×10⁻⁷ m, further preferably, 1×10⁻⁷ m to 1.8×10⁻⁷ m. Note that theorganic semiconductors are often classified into p-type and re-type. Thep-type denotes that the electron holes can be easily transported, andthe n-type denotes that the electrons can be easily transported. Theorganic semiconductor is not limited to the interpretation that theelectron holes or the electrons are included as thermally excitedmajority carriers as in an inorganic semiconductor.

Alternatively, examples of the materials included in the organicphotoelectric conversion layer for photoelectric conversion of greenlight include a rhodamine dye, a merocyanine dye, a quinacridonederivative, and a subphthalocyanine dye (subphthalocyanine derivative).Examples of the materials included in the organic photoelectricconversion layer for photoelectric conversion of blue light include acoumaric acid dye, tris-8-hydroxyquinoline aluminum (Alq3), and amerocyanine dye. Examples of the materials included in the organicphotoelectric conversion layer for photoelectric conversion of red lightinclude a phthalocyanine dye and a subphthalocyanine dye(subphthalocyanine derivative).

Alternatively, examples of the inorganic materials included in thephotoelectric conversion layer include crystalline silicon, amorphoussilicon, microcrystalline silicone, crystalline selenium, amorphousselenium, chalcopyrite compounds, such as CIGS (CuInGaSe), CIS(CuInSe₂), CuInS₂, CuAlS₂, CuAlSe₂, CuGaS₂, CuGaSe₂, AgAlS₂, AgAlSe₂,AgInS₂, and AgInSe₂, group III-V compounds, such as GaAs, InP, AlGaAs,InGaP, AlGaInP, and InGaAsP, and compound semiconductors of CdSe, CdS,Bi₂Se₃, Bi₂S₃, ZnSe, ZnS, PbSe, PbS, and the like. In addition, quantumdots including these materials can also be used for the photoelectricconversion layer.

The solid-state imaging apparatuses according to the first and secondaspects of the present disclosure and the solid-state imagingapparatuses of the first and second configurations can providesingle-plate color solid-state imaging apparatuses.

In the solid-state imaging apparatuses according to the second aspect ofthe present disclosure including the stacked imaging elements, theimaging elements sensitive to light at a plurality of types ofwavelengths in the light incident direction within the same pixel arestacked to provide one pixel, unlike in the solid-state imagingapparatuses including imaging elements of Bayer array (that is, notusing a color filter layer to separate blue, green, and red). Therefore,the sensitivity can be improved, and the pixel density per unit volumecan be improved. In addition, the absorption coefficients of the organicmaterials are high, and the film thickness of the organic photoelectricconversion layer can be thinner than a Si-based photoelectric conversionlayer in the past. This reduces light leakage from adjacent pixels andalleviates restrictions on light incident angle. Furthermore, in theSi-based imaging elements in the past, an interpolation process isexecuted for the pixels of three colors to create color signals, andtherefore, false colors are generated. In the solid-state imagingapparatus according to the second aspect of the present disclosureincluding the stacked imaging elements, the generation of the falsecolors is suppressed. The organic photoelectric conversion layer alsofunctions as a color filter layer, and the colors can he separatedwithout arranging the color filter layer.

On the other hand, in the solid-state imaging apparatus according to thefirst aspect of the present disclosure, the color filter layer can beused to alleviate the requirements for the spectral characteristics ofblue, green, and red, and the mass productivity is high. Examples of thearray of the imaging elements in the solid-state imaging apparatusaccording to the first aspect of the present disclosure include theBayer array, as well as an interline array, a G stripe RB checkeredarray, a G stripe RB full checkered array, a checkered complementarycolor array, a stripe array, a diagonal stripe array, a primary colordifference array, a field color difference sequential array, a framecolor difference sequential array, a MOS array, an improved. MOS array,a frame interleave array, and a field interleave array. Here, oneimaging element provides one pixel (or subpixel).

Examples of the color filter layers (wavelength selection means) includefilter layers that transmit not only red, green, and blue, but alsospecific wavelengths, such as cyan, magenta, and yellow, depending onthe case. The color filter layer can include not only a color filterlayer of organic materials using organic compounds, such as pigments anddyes, but also a thin film including inorganic materials, such asphotonic crystal, a wavelength selection element using plasmon (colorfilter layer with conductor grid structure including grid hole structurein conductor thin film, see, for example, Japanese Patent Laid-Open No.2008-177191), and amorphous silicon.

The pixel region provided with the plurality of arrayed imaging elementsand the like of the present disclosure includes a plurality of pixelssystematically arranged in a two-dimensional array. The pixel regionusually includes: an effective pixel region in which the light isactually received to generate signal charge through photoelectricconversion, and the signal charge is amplified and read out to the drivecircuit; and a black reference pixel region (also called optical blackpixel region (OPB)) for outputting optical black as a standard for blacklevel. The black reference pixel region is usually arranged on theperiphery of the effective pixel region.

In the imaging element and the like of the present disclosure includingvarious preferred modes and configurations described above, the light isapplied, and photoelectric conversion occurs in the photoelectricconversion layer. Carrier separation of electron holes (holes) andelectrons is conducted. In addition, the electrode from which theelectron holes are extracted is an anode, and the electrode from whichthe electrons are extracted is a cathode. The first electrode providesthe cathode, and the second electrode provides the anode.

The first electrode, the charge storage electrode, the transfer controlelectrode, the discharge electrode, and the second electrode can includetransparent conductive materials. The first electrode, the chargestorage electrode, the transfer control electrode, and the dischargeelectrode will be collectively referred to as “first electrode and thelike” in some cases. Alternatively, in a case where the imaging elementand the like of the present disclosure are arranged on a plane as in,for example, a Bayer array, the second electrode can include atransparent conductive material, and the first electrode and the likecan include a metal material. In this case, specifically, the secondelectrode positioned on the light incident side can include atransparent conductive material, and the first electrode and the likecan include, for example, Al—Nd. (alloy of aluminum and neodymium) orASC (alloy of aluminum, samarium, and copper). An electrode including atransparent conductive material will be referred to as a “transparentelectrode” in some cases. Here, Here, it is desirable that the band-gapenergy of the transparent conductive material be equal to or greaterthan 2.5 eV, preferably, equal to or greater than 3.1 eV. An example ofthe transparent conductive material included in the transparentelectrode includes conductive metal oxide. Specifically, examples of thetransparent conductive material include indium oxide, indium-tin oxide(including ITO, Indium Tin Oxide, Sn-doped In₂O₃, crystalline ITO, andamorphous ITO), indium-zinc oxide (IZO, Indium Zinc Oxide) obtained byadding indium as a dopant to zinc oxide, indium-gallium oxide (IGO)obtained by adding indium as a dopant to gallium oxide,indium-gallium-zinc oxide (IGZO, In—GaZnO₄) obtained by adding indiumand gallium as dopants to zinc oxide, indium-tin-zinc oxide (ITZO)obtained by adding indium and tin as dopants to zinc oxide, IFO (F-dopedIn₂O₃), tin oxide (SnO₂), ATO (Sb-doped SnO₂), FTO (F-doped SnO₂) zincoxide (including ZnO doped with other elements), aluminum-zinc oxide(AGO) obtained by adding aluminum as a dopant to zinc oxide,gallium-zinc oxide (GZO) obtained by adding gallium as a dopant to zincoxide, titanium oxide (TiO₂), niobium-titanium oxide (TNO) obtained byadding niobium as a dopant to titanium oxide, antimony oxide, spineloxide, and oxide with YbFe₂O₄ structure. Alternatively, the transparentelectrode can include gallium oxide, titanium oxide, niobium oxide,nickel oxide or the like as a mother layer. An example of the thicknessof the transparent electrode includes 2×10⁻⁸ m to 2×10⁻⁷ m, preferably,3×10⁻⁸ m to 1×10⁻⁷ m. In a case where the first electrode needs to betransparent, it is preferable that the discharge electrode also includea transparent conductive material from the viewpoint of simplificationof the manufacturing process.

Alternatively, in a case where transparency is not necessary, it ispreferable to use a conductive material with a low work function (forexample, ϕ=3.5 eV to 4.5 eV) as a conductive material included in thecathode with a function of an electrode for extracting the electrons.Specifically, examples of the conductive material include alkali metal(for example, Li, Na, K, or the like) and fluoride or oxide of thealkali metal, alkaline earth metal (for example, Mg, Ca, or the like)and fluoride or oxide of the alkaline earth metal, aluminum (Al), zinc(Zn), tin (Sn), thallium (Tl), a sodium-potassium alloy, analuminum-lithium alloy, a magnesium-silver alloy, indium, rare earthmetal such as ytterbium, and alloys of these. Alternatively, examples ofthe material included in the cathode include metal, such as platinum(Pt), gold (Au), palladium (Pd), chromium (Cr), nickel (Ni), aluminum(Al), silver (Ag), tantalum (Ta), tungsten. (W), copper (Cu), titanium(Ti), indium (in), tin (Sn), iron (Fe), cobalt (Co), and molybdenum(Mo), alloys containing these metal elements, conductive particlesincluding these metals, conductive particles of alloys containing thesemetals, polysilicon containing impurities, a carbon material, an oxidesemiconductor material, a carbon nanotube, and a conductive materialsuch as graphene. The cathode can also have a stacked structure oflayers containing these elements. Furthermore, examples of the materialincluded in the cathode also include organic materials (conductivepolymers) such as poly(3,4-ethylenedioxythiophene-poly(styrenesulfonate)[PEDOT/PSS]. In addition, these conductive materials may be mixed with abinder (polymer) to obtain a paste or an ink, and the paste or the inkmay be cured and used as an electrode.

A dry method or a wet method can be used as a deposition method of thefirst electrode and the like or the second electrode (cathode or anode).Examples of the dry method include a physical vapor deposition method(PVD method) and a chemical vapor deposition method (CVD method).Examples of the deposition method using the principle of PVD methodinclude a vacuum evaporation method using resistance heating or radiofrequency heating, an EB (electron beam) evaporation method, varioussputtering methods (magnetron sputtering method, RE-DC coupled biassputtering method, ECR sputtering method, facing target sputteringmethod, and RE sputtering method), an ion plating method, a laserablation method, a molecular beam epitaxy method, and a laser transfermethod. In addition, examples of the CVD method include a plasma CVDmethod, a thermal CVD method, an organic metal (MO) CVD method, and anoptical CVD method. On the other hand, examples of the wet methodinclude methods, such as an electroplating method, an electrolessplating method, a spin coating method, an inkjet method, a spray coatingmethod, a stamping method, a microcontact printing method, aflexographic printing method, an offset printing method, a gravureprinting method, and a dipping method. Examples of a patterning methodinclude chemical etching, such as a shadow mask, laser transfer, andphotolithography, and physical etching using ultraviolet light, laser,or the like. Examples of a planarization method of the first electrodeand the like and the second electrode include a laser planarizationmethod, a reflow method, and a CMP (Chemical Mechanical Polishing)method.

Examples of the materials included in the insulating layer include notonly inorganic insulating materials like metal oxide high dielectricinsulating materials such as: a silicon oxide material; a siliconnitride (SiN_(Y)) and aluminum oxide (Al₂O₃), but also organicinsulating materials (organic polymers) such as: polymethyl methacrylate(PMMA); polyvinyl phenol (PVP) polyvinyl alcohol (PVA); polyimide;polycarbonate (PC) polyethylene terephthalate (PET); polystyrene; asilanol derivative (silane coupling agent) such asN-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AEAPTMS),3-mercaptopropyltrimethoxysilane (MPTMS), and octadecyltrichlorosilane(OTS); a novolac phenolic resin; a fluororesin; and straight chainhydrocarbons, such as octadecanethiol and dodecyl isocyanate, including,on one end, a functional group that can be combined with a controlelectrode. A combination of these can also be used. Examples of thesilicon oxide material include silicon oxide (SiOx), BPSG, PSG, BSG,AsSG, PbSG, silicon oxynitride (SiON), SOG (spin on glass), and lowdielectric insulating materials (for example, polyarylether,cycloperfluorocarbon polymer, benzocyclobutene, cyclic fluororesin,polytetrafluoroethylene, fluorinated aryl ether, fluorinated polyimide,amorphous carbon, and organic SOG). The insulating layer can have asingle-layer configuration, or a plurality of layers (for example twolayers) can be stacked. In the latter case, an insulating layer/lowerlayer can be formed at least over the charge storage electrode and inthe area between the charge storage electrode and the first electrode. Aplanarization process can be applied to the insulating layer/lower layerto leave the insulating layer/lower layer at least in the region betweenthe charge storage electrode and the first electrode. An insulatinglayer/upper layer can be formed over the insulating layer/lower layerand the charge storage electrode. In this way, the insulating layer canbe certainly planarized. These materials is also only required to beappropriately selected for the materials included in various interlayerinsulating layers and insulating material films.

The configurations and the structures of the floating diffusion layer,the amplification transistor, the reset transistor, and the selectiontransistor included in the control unit can be similar to theconfigurations and the structures of the floating diffusion layer,amplification transistor, reset transistor, and selection transistor inthe past. The drive circuit can also have well-known configuration andstructure.

The first electrode is connected to the floating diffusion layer and agate portion of the amplification transistor, and a contact hole portionis only required to be formed for the connection of the first electrodeto the floating diffusion layer and the gate portion of theamplification transistor. Examples of the materials included in thecontact hole portion include polysilicon doped with impurities, highmelting point metal and metal silicide, such as tungsten, Ti, Pt, Pd,Cu, TiW, TiN, TiNW, WSi₂, and MoSi₂ or the like, and a stacked structureof layers including these materials (for example, Ti/TiN/W).

A first carrier blocking layer may be provided between the inorganicoxide semiconductor material layer and the first electrode, and a secondcarrier blocking layer may be provided between the organic photoelectricconversion layer and the second electrode. In addition, a first chargeinjection layer may be provided between the first carrier blocking layerand the first electrode, and a second charge injection layer may beprovided between the second carrier blocking layer and the secondelectrode. For example, examples of the materials included in theelectron injection layer include alkali metal, such as lithium (Li),sodium (Na), and potassium (K), fluoride or oxide of the alkali metal,alkaline earth metal, such as magnesium (Mg) and calcium (Ca), andfluoride or oxide of the alkaline earth metal.

Examples of the deposition method of various organic layers include adry deposition method and a wet deposition method. Examples of the drydeposition method include a vacuum evaporation method using resistanceheating, radio frequency heating, or electron beam heating, a flashevaporation method, a plasma deposition method, an NB evaporationmethod, various sputtering methods (bipolar sputtering method, DCsputtering method, DC magnetron sputtering method, RE sputtering method,magnetron sputtering method, RF-DC coupled bias sputtering method, NCRsputtering method, facing target sputtering method, RE sputteringmethod, and ion beam sputtering method), a DC (Direct Current) method,an RE method, a multi-cathode method, an activation reaction method, anelectric field evaporation method, various ion plating methods, such asan RF ion plating method and a reactive ion plating method, a laserablation method, a molecular beam epitaxy method, a laser transfermethod, and a molecular beam epitaxy method (TBE method). In addition,examples of the CVD method include a plasma CVD method, a thermal CVDmethod, an MOCVD method, and an optical CVD method. On the other hand,specific examples of the wet method include: a spin coating method; adipping method; a casting method; a microcontact printing method; a dropcasting method; various printing methods, such as a screen printingmethod, an inkjet printing method, an offset printing method, a gravureprinting method, and a flexographic printing method; a stamping method;a spraying method; and various coating methods, such as an air doctorcoater method, a blade coater method, a rod coater method, a knifecoater method, a squeeze coater method, a reverse roll coater method, atransfer roll coater method, a gravure coater method, a kiss coatermethod, a cast coater method, a spray coater method, a slit orificecoater method, and a calendar coater method. In the coating method,examples of the solvent include nonpolar or low-polarity organicsolvents, such as toluene, chloroform, hexane, and ethanol. Examples ofthe patterning method include chemical etching, such as a shadow mask,laser transfer, and photolithography, and physical etching usingultraviolet light, laser, or the like. A laser planarization method, areflow method, and the like can be used as planarization techniques ofvarious organic layers.

Two or more types of imaging elements of the first to sixthconfigurations described above can be appropriately combined asnecessary.

As described above, the on-chip micro lens and the light shielding layermay be provided on the imaging element or the solid-state imagingapparatus as necessary, and the drive circuit and the wire for drivingthe imaging element are provided. A shutter for controlling the lightincident on the imaging element may be arranged as necessary, and anoptical cut filter may be provided according to the purpose of thesolid-state imaging apparatus.

In addition, the solid-state imaging apparatus of the first and secondconfigurations can be in a mode where one on-chip micro lens is arrangedon the upper side of one imaging element and the like of the presentdisclosure. Alternatively, two imaging elements and the like of thepresent disclosure can be included in the imaging element block, and oneon-chip micro lens can be arranged on the upper side of the imagingelement block.

For example, in a case of stacking the solid-state imaging apparatus anda readout integrated circuit (ROIC), a drive substrate, which isprovided with the readout integrated circuit and a connection portioncontaining copper (Cu), and the imaging element, which is provided witha connection portion, can be placed on top of each other so that theconnection portions are in contact with each other. In this way, theconnection portions can be bonded to stack the solid-state imagingapparatus and the readout integrated circuit. Solder bumps or the likecan also be used to bond the connection portions.

Furthermore, a driving method for driving the solid-state imagingapparatuses according to the first and second aspects of the presentdisclosure can be a driving method of the solid-state imaging apparatusrepeating the steps of:

releasing the charge in the first electrodes all at once to the outsideof the system while storing the charge in the inorganic oxidesemiconductor material layers (or the inorganic oxide semiconductormaterial layers and the photoelectric conversion layers) in all of theimaging elements; and

subsequently, transferring the charge stored in the inorganic oxidesemiconductor material layers (or the inorganic oxide semiconductormaterial layers and the photoelectric conversion layers) all at once tothe first electrodes in all of the imaging elements, and after thecompletion of the transfer, sequentially reading the charge transferredto the first electrodes in the imaging elements,

In the driving method of the solid-state imaging apparatus, the lightincident from the second electrode side is not incident on the firstelectrode in each imaging element. The charge in the first electrodes isreleased to the outside of the system ail at once while the charge isstored in the inorganic oxide semiconductor material layer and the likein all of the imaging elements. Therefore, the first electrodes can becertainly reset at the same time in all of the imaging elements. Inaddition, subsequently, the charge stored in the inorganic oxidesemiconductor material layers and the like is transferred all at once tothe first electrodes in all of the imaging elements. After thecompletion of the transfer, the imaging elements sequentially read thecharge transferred to the first electrodes. Therefore, a so-calledglobal shutter function can be easily realized.

Examples of the imaging element of the present disclosure include a CCDelement, a CMOS image sensor, a CIS (Contact Image Sensor), and a CMD(Charge Modulation Device) signal-amplification image sensor. Thesolid-state imaging apparatuses according to the first and secondaspects of the present disclosure and the solid-state imagingapparatuses of the first and second configurations can be included in,for example, a digital still camera, a video camera, a camcorder, asurveillance camera, an on-vehicle camera, a smartphone camera, a userinterface camera for gaming, and a biometric authentication camera.

Embodiment 1

Embodiment 1 relates to the imaging elements according to the first tothird aspects of the present disclosure, the stacked imaging element ofthe present disclosure, and the solid-state imaging apparatus accordingto the second aspect of the present disclosure. FIG. 1 illustrates aschematic partial cross-sectional view of the imaging element and thestacked imaging element (hereinafter, simply referred to as “imagingelement”) of Embodiment 1. FIGS. 2 and 3 illustrate equivalent circuitdiagrams of the imaging element of Embodiment 1. FIG. 4 illustrates aschematic layout drawing of a first electrode and a charge storageelectrode included in a photoelectric conversion unit and transistors ofa control unit included in the imaging element, of Embodiment 1. FIG. 5schematically illustrates a state of potential in each section duringoperation of the imaging element of Embodiment 1. FIG. 6A illustrates anequivalent circuit diagram for describing each section of the imagingelement of Embodiment 1. In addition, FIG. 7 illustrates a schematiclayout drawing of the first electrode and the charge storage electrodeincluded in the photoelectric conversion unit of the imaging element ofEmbodiment 1. FIG. 8 illustrates a schematic perspective view of thefirst electrode, the charge storage electrode, a second electrode, and acontact hole portion. Furthermore, FIG. 79 illustrates a conceptualdiagram of the sold-state imaging apparatus of Embodiment 1.

The imaging element of Embodiment 1 includes a photoelectric conversionunit including a first electrode 21, a photoelectric conversion layer23A, and a second electrode 22 that are stacked, and an inorganic oxidesemiconductor material layer 23B is formed between the first electrode21 and the photoelectric conversion layer 23A. In addition, theinorganic oxide semiconductor material layer 23B includes at least twotypes of elements selected from the group consisting of indium,tungsten, tin, and zinc. Alternatively, a LUMO value Si of the materialincluded in the part of the photoelectric conversion layer 23Apositioned near the inorganic oxide semiconductor material layer 23B anda LUMO value 52 of the material included in the inorganic oxidesemiconductor material layer 23B satisfy the following Expression (A),preferably, the following Expression (B).

E1−E2<0.2 eV (A)

E1−E2<0.1 eV (B)

Alternatively, the mobility of the material included in the inorganicoxide semiconductor material layer 23B is equal to or greater than 10cm²/V·s.

The imaging element of Embodiment 1 corresponding to the imaging elementaccording to the first aspect of the present disclosure also satisfiesExpression (A), preferably, Expression (B). In addition, the mobility ofthe material included in the inorganic oxide semiconductor materiallayer 23B is also equal to or greater than 10 cm²/V·s in the imagingelement of Embodiment 1 corresponding to the imaging elements accordingto the first and second aspects of the present disclosure.

In addition, the photoelectric conversion unit in the imaging element ofEmbodiment 1 further includes an insulating layer 82 and a chargestorage electrode 24 arranged apart from the first electrode 21 andarranged to face the inorganic oxide semiconductor material layer 231Bthrough the insulating layer 82. Note that the light is incident fromthe second electrode 22.

The stacked imaging element of Embodiment 1 includes at least oneimaging element of Embodiment 1. In addition, the solid-state imagingapparatus of Embodiment 1 includes a plurality of stacked imagingelements of Embodiment 1. Furthermore, the solid-state imaging apparatusof Embodiment 1 is included in, for example, a digital still camera, avideo camera, a camcorder, a surveillance camera, an on-vehicle(car-mounted camera), a smartphone camera, a user interface camera forgaming, a biometric authentication camera, and the like.

Hereinafter, various characteristics of the imaging element ofEmbodiment 1 will be described first, and then the imaging element andthe solid-state imaging apparatus of Embodiment 1 will be described indetail.

An oxygen gas introduction amount (oxygen gas partial pressure) informing the inorganic oxide semiconductor material layer 23B based onthe sputtering method can be controlled to control the energy level ofthe inorganic oxide semiconductor material layer 23B. It is preferableto set the oxygen gas partial pressure to 0.005 (0.5%) to 0.02 (2%).

The film thickness of the inorganic oxide semiconductor material layer23B is set to 50 nm, and IWO is used to form the inorganic oxidesemiconductor material layer 23B. The following Table 1 indicatesresults of obtaining a relationship between the oxygen gas partialpressure and the energy level obtained by inverse photoelectronspectroscopy. In the imaging element of Embodiment 1, the oxygen gasintroduction amount (oxygen gas partial pressure) in forming theinorganic oxide semiconductor material layer 23B based on the sputteringmethod can be controlled to control the energy level of the inorganicoxide semiconductor material layer 23B. Note that the content rate ofoxygen is lower than the oxygen content rate of stoichiometriccomposition in the inorganic oxide semiconductor material layer 23B.

TABLE 1 Oxygen gas partial pressure Energy level 0.5% 4.3 eV 2.0% 4.5 eV

Next, regarding the photoelectric conversion layer 23A and the inorganicoxide semiconductor material layer 23B, the energy level of theinorganic oxide semiconductor material layer 23B, the energy leveldifference (E₁−E₂) between the photoelectric conversion layer 23A andthe inorganic oxide semiconductor material layer 23B, and the mobilityof the material included in the inorganic oxide semiconductor materiallayer 23B are checked. The conditions are divided into three conditionsas illustrated in Table 2. Here, the LUMO value E₁ of the materialincluded in the part of the photoelectric conversion layer 23Apositioned near the inorganic oxide semiconductor material layer 23B isset to 4.5 eV. In a first condition, there is an energy level difference(E₁−E₂) of 0.2 eV. In a second condition, the energy level difference(E₁−E₂) is improved compared to the first condition. In a thirdcondition, the mobility is further improved compared to the secondcondition. The transfer characteristics under these three conditions areevaluated in a device simulation based on the imaging element with thestructure illustrated in FIG. 1.

Note that in the first condition, IGZO is used as the material includedin the inorganic oxide semiconductor material layer 23B. In the secondcondition, ZTO or ITZO is used as the material included in the inorganicoxide semiconductor material layer 23B. In the third condition, IWZO orIWO is used as the material included in the inorganic oxidesemiconductor material layer 23B. In addition, the film thickness of theinorganic oxide semiconductor material layer 23B is 50 nm. Furthermore,the photoelectric conversion layer 23A includes quinacridone, and thethickness is 0.1 μm.

TABLE 2 First Second Third condition condition condition Inorganic oxidesemiconductor 4.3 eV 4.5 eV 4.5 eV material layer Energy leveldifference (E₁ − E₂) 0.2 eV 0 eV 0 V Mobility (Unit: cm²/V · s) 9 10 30

FIG. 76 illustrates evaluation results of the transfer characteristics.A relative amount of electrons in a state in which the electrons areattracted to an upper side of the charge storage electrode 24 is 1×10°in FIG. 76. In addition, a relative amount of electrons in a state inwhich all of the electrons attracted to the upper side of the chargestorage electrode 24 are transferred to the first electrode 21 is I x10® in FIG. 76. The time of transfer (referred to as “transfer time”) ofall of the electrons attracted to the upper side of the charge storageelectrode 24 to the first electrode 21 is indicated on the horizontalaxis of FIG. 76. In FIG. 76, “A” indicates evaluation results of thetransfer characteristics under the first condition, “B” indicatesevaluation results of the transfer characteristics under the secondcondition, and “C” indicates evaluation results of the transfercharacteristics under the third condition. The transfer time is shorterin the second condition than is the first condition and shorter in thethird condition than in the second condition.

To satisfy characteristics without remaining transfer charge that arerequired for the imaging element, appropriate transfer time for therelative amount of electrons to reach 1×10⁻⁴ is 1×10⁻⁷ seconds. Thesecond condition is excellent is satisfying the transfer time, and thethird condition is more excellent. That is, the inorganic oxidesemiconductor material layer 23B includes at least two types of elementsselected from the group consisting of indium, tungsten, tin, and zinc.In addition, the LUMO value E₁ of the material included in the part ofthe photoelectric conversion layer 23A positioned near the inorganicoxide semiconductor material layer 23B and the LUMO value E₂ of thematerial included in the inorganic oxide semiconductor material layer23B satisfy

E1×E2<0.2 eV,

preferably,

E1−E2<0.1 eV.

Furthermore, the mobility of the material included in the inorganicoxide semiconductor material layer 23B is equal to or greater than 10 cm²/V·s.

FIG. 77 illustrates results of evaluation of the transfercharacteristics where the LUMO value E₁ of the photoelectric conversionlayer 23A is 4.5 eV, and the LUMO value E₂ of the material included inthe inorganic oxide semiconductor material layer 23B 4.4 eV (see “C” ofFIG. 77), 4.5 eV (see “B” of FIG. 77), 4.6 eV (see “A” of FIG. 77), or4.7 eV (see “A” of FIG. 77). Note that the data of 4.6 eV and the dataof 4.7 eV overlap. The results indicate that the higher the LUMO valueE₂, the more excellent the transfer characteristics. Therefore, theresults indicate that forming the layers so that the LUMO value E₂ ofthe inorganic oxide semiconductor material layer 23B is greater than theLUMO value E₁ of the photoelectric conversion layer 23A is a morepreferable factor for further improving the transfer characteristics.

In addition, FIGS. 78A and 78B illustrate evaluation results of darkcurrent characteristics (J_(dk)) at 60° C. at the time of photoelectricconversion in the photoelectric conversion layer 23A and externalquantum efficiency characteristics (EQE) at room temperature (25° C.),where ZTO is included in the inorganic oxide semiconductor materiallayer 23B.

The evaluation sample has a structure in which a first electrodeincluding ITO is formed on a substrate, and an inorganic oxidesemiconductor material layer, a photoelectric conversion layer, a bufferlayer including MoOX, and a second electrode are sequentially stacked onthe first electrode. Here, the thickness of the inorganic oxidesemiconductor material layer is 20 nm or 100 nm. In addition, acomparison sample has a structure in which a first electrode includingITO is formed on a substrate, and a photoelectric conversion layer, abuffer layer including MoO_(x), and a second electrode are sequentiallystacked on the first electrode. That is, the inorganic oxidesemiconductor material layer is not formed in the comparison sample.Regarding the dark current characteristics (J_(dk)), it is understoodthat the evaluation sample has a performance correspond to thecomparison sample (see “C” of FIG. 78A). Note that see “A” of FIGS. 78Aand 78B for the data where the thickness of the inorganic oxidesemiconductor material layer is 100 nm. In addition, see “B” of FIGS.78A and 78B for the data where the thickness of the inorganic oxidesemiconductor material layer is 20 nm. In FIG. 78A, graphs (data of “A”and “B”) of the dark current characteristics of two types of evaluationsamples mostly overlap. In addition, when a positive bias of 1 volt isapplied, the external quantum efficiency characteristics (EQE) of thecomparison sample (see “C” of FIG. 78B) are 80%, while the evaluationsample indicates a higher value. In this way, it is confirmed that in acase where the inorganic oxide semiconductor material is formed, thecharacteristics are correspond to or more excellent than thecharacteristics of a case where the inorganic oxide semiconductormaterial layer is not formed.

In addition, more specifically, the inorganic oxide semiconductormaterial layer 23B does not contain gallium atoms, and the inorganicoxide semiconductor material layer 23B includes IWO, IWZG, ITZO, or ZTO.Here, it is understood from X-ray diffraction results that the inorganicoxide semiconductor material layer 23B is amorphous (for example,amorphous material not locally including crystal structure).Furthermore, surface roughness Ra of the inorganic oxide semiconductormaterial layer 23B at the interface between the photoelectric conversionlayer 23A and the inorganic oxide semiconductor material layer 23B isequal to or smaller than 1.5 nm, and a value of root means squareroughness Rq of the inorganic oxide semiconductor material layer isequal to or smaller than 2.5 nm. Specifically, the values are asfollows.

-   Ra=0.8 nm-   Rq=2.1 nm

In addition, the surface roughness Ra of the charge storage electrode 24is equal to or smaller than 1.5 nm, and a value of the root means squareroughness Rq of the charge storage electrode 24 is equal to or smallerthan 2.5 nm. Specifically, the values are as follows.

-   Ra=0.7 nm-   Rq=2.3 nm

Furthermore, the light transmittance of the inorganic oxidesemiconductor material layer 23B with respect to the light atwavelengths of 400 to 660 nm is equal to or greater than 65%(specifically, 80%), and the light transmittance of the charge storageelectrode 24 with respect to the light at wavelengths of 400 to 660 nmis also equal to or greater than 65% (specifically, 75%). A sheetresistance value of the charge storage electrode 24 is 3×10 Ω/□ to1×10³Ω/□ (specifically, 84 Ω/□).

Hereinafter, the imaging element and the solid-state imaging apparatusof Embodiment 1 will be described in detail.

The imaging element of Embodiment 1 further includes a semiconductorsubstrate (more specifically, silicon semiconductor layer) 70, and thephotoelectric conversion unit is arranged on the upper side of thesemiconductor substrate 70. In addition, the imaging element furtherincludes a control unit provided on the semiconductor substrate 70 andincluding a drive circuit connected to the first electrode 21 and thesecond electrode 22. Here, the light incident surface in thesemiconductor substrate 70 is the upper side, and the opposite side ofthe semiconductor substrate 70 is the lower side 2 wiring layer 62including a plurality of wires is provided on the lower side of thesemiconductor substrate 70.

At least a floating diffusion layer FD₁ and an amplification transistorTR1 _(amp) included in the control unit are provided on thesemiconductor substrate 70, and the first electrode 21 is connected tothe floating diffusion layer FD₁ and a gate portion of the amplificationtransistor TR1 _(amp). A reset transistor TR1 _(rst) and a selectiontransistor TR1 _(sel) included in the control unit are further providedon the semiconductor substrate 70. The floating diffusion layer FD₁ isconnected to one source/drain region of the reset transistor TR1 _(rst).One source/drain region of the amplification transistor TR1 _(amp) isconnected to one source/drain region of the selection transistor TR1_(sel). The other source/drain region of the selection transistor TR1_(sel) is connected to a signal line VSL₁. The amplification transistorTR1 _(amp), the reset transistor TR1 _(rst), and the selectiontransistor TR1 _(sel) are included in the drive circuit.

Specifically, the imaging element of Embodiment 1 is a back illuminatedtype imaging element. The imaging element has a stacked structure ofthree imaging elements including: a green light imaging element of firsttype in Embodiment 1 (hereinafter, referred to as “first imagingelement”) sensitive to green light, the green light imaging elementincluding a green light photoelectric conversion layer of first type forabsorbing green light; a blue light imaging element in the past ofsecond type (hereinafter, referred to as “second imaging element”)sensitive to blue light, the blue light imaging element including a bluelight photoelectric conversion layer of second type for absorbing bluelight; and a red light imaging element in the past of second type(hereinafter, referred to as “third imaging element”) sensitive to redlight, the red light imaging element including a red light photoelectricconversion layer of second type for absorbing red light. Here, the redlight imaging element (third imaging element) and the blue light imagingelement (second imaging element) are provided in the semiconductorsubstrate 70, and the second imaging element is positioned on the lightincident side with respect to the third imaging element. In addition,the green light imaging element (first imaging element) is provided onthe upper side of the blue light imaging element (second imagingelement). The stacked structure of the first imaging element, the secondimaging element, and the third imaging element is included in one pixel.Color filter layers are not provided.

In the first imaging element, the first electrode 21 and the chargestorage electrode 24 are formed apart from each other on an interlayerinsulating layer 81. The interlayer insulating layer 81 and the chargestorage electrode 24 are covered by the insulating layer 82. Theinorganic oxide semiconductor material layer 23B and the photoelectricconversion layer 23A are formed on the insulating layer 82, and thesecond electrode 22 is formed on the photoelectric conversion layer 23A.An insulating layer 83 is formed over the entire surface including thesecond electrode 22, and an on-chip micro lens 14 is provided on theinsulating layer 83. Color filter layers are not provided. The firstelectrode 21, the charge storage electrode 24, and the second electrode22 include, for example, transparent electrodes containing ITO (workfunction: approximately 4.4 eV). The inorganic oxide semiconductormaterial layer 23B contains, for example, IWZO, IWO, ZTO, or ITZO. Thephotoelectric conversion layer 23A includes a layer containing awell-known organic photoelectric conversion material sensitive to atleast green light (for example, organic material such as rhodamine dye,merocyanine dye, and quinacridone). The interlayer insulating layer 81and the insulating layers 82 and 83 include a well-known insulatingmaterial (for example, SiO₂ or SiN). The inorganic oxide semiconductormaterial layer 23B and the first electrode 21 are connected through aconnection portion 67 provided on the insulating layer 82. The inorganicoxide semiconductor material layer 23B extends in the connection portion67. That is, the inorganic oxide semiconductor material layer 23Bextends in an opening portion 85 provided on the insulating layer 82 andis connected to the first electrode 21.

The charge storage electrode 24 is connected to the drive circuit.Specifically, the charge storage electrode 24 is connected to a verticaldrive circuit 112 included in the drive circuit through a connectionhole 66, a pad portion 64, and a wire V_(OA) provided in the interlayerinsulating layer 81.

The size of the charge storage electrode 24 is larger than the firstelectrode 21. Although not limited, it is preferable to satisfy

4≤S₁′/S₁,

where S is the area of the charge storage electrode 24, and Si is thearea of the first electrode 21. Although not limited,

S₁′/S₁=8

is set in Embodiment 1, for example. Note that in Embodiments 7 to 10described later, the sizes of three photoelectric conversion unitsegments 10′₁, 10′₂, and 10′₃) are the same size, and the plane shapesare also the same.

An element separation region 71 is formed on the side of a first surface(front surface) 70A of the semiconductor substrate 70, and an oxide film72 is formed on the first surface 70A of the semiconductor substrate 70.Furthermore, the reset transistor TR1 _(rst), the amplificationtransistor TR1 _(amp), and the selection transistor TR1 _(sel) includedin the control unit of the first imaging element are provided on thefirst surface side of the semiconductor substrate 70, and the firstfloating diffusion layer FD₁ is further provided.

The reset transistor TR1 _(rst) includes a gate portion 51, a channelformation region 51A, and source/drain regions 51B and 51C. The gateportion 51 of the reset transistor TR1 _(rst) is connected to a resetline RST1. One source/drain region 51C of the reset transistor TR1_(rst) also serves as the first floating diffusion layer FD₁, and theother source/drain region 51B is connected to a power source V_(DD).

The first electrode 21 is connected to one source/drain region 51C(first floating diffusion layer FD₁) of the reset transistor TR1 _(rst)through a connection hole 65 and a pad portion 63 provided in theinterlayer insulating layer 81, through a contact hole portion 61 formedon the semiconductor substrate 70 and an interlayer insulating layer 76,and through the wiring layer 62 formed on the interlayer insulatinglayer 76.

The amplification transistor TR1 _(amp) includes a sate portion 52, achannel formation region 52A, and source/drain regions 52B and 52C. Thegate portion 52 is connected to the first electrode 21 and onesource/drain region 51C (first floating diffusion layer FD₁) of thereset transistor TR1 _(rst) through the wiring layer 62. In addition,one source/drain region 52B is connected to the power source V_(DD).

The selection transistor TR1 _(sel) includes a gate portion 53, achannel formation region 53A, and source/drain regions 53B and 53C. Thegate portion 53 is connected to a selection line SEL₁. In addition, onesource/drain region 53B shares the region with the other source/drainregion 52C included in the amplification transistor TR1 _(amp), and theother source/drain region 53C is connected to the signal line (dataoutput line) VSL₁ (117).

The second imaging element includes an n-type semiconductor region 41 asa photoelectric conversion layer provided on the semiconductor substrate70. A gate portion 45 of a transfer transistor TR2 _(trs) including avertical transistor extends to the n-type semiconductor region 41 and isconnected to a transfer gate line TG₂. In addition, a second floatingdiffusion layer FD₂ is provided in a region 45C of the semiconductorsubstrate 70 near the gate portion 45 of the transfer transistor TR2_(trs). The charge stored in the n-type semiconductor region 41 is readout to the second floating diffusion layer FD₂ through a transferchannel formed along the gate portion 45.

The second imaging element is further provided with a reset transistorTR2 _(rst), an amplification transistor TR2 _(amp), and a selectiontransistor TR2 _(sel) included in the control unit of the second imagingelement on the first surface side of the semiconductor substrate 70.

The reset transistor TR2 _(rst) includes a gate portion, a channelformation region, and source/drain regions. The gate portion of thereset transistor TR2 _(rst) is connected to a reset line RST₂. Onesource/drain region of the reset transistor TR2 _(rst) is connected tothe power source V_(DD). The other source/drain region also serves asthe second floating diffusion layer FD₂.

The amplification transistor TR2 _(amp) includes a gate portion, achannel formation region, and source/drain regions. The gate portion isconnected to the other source/drain region (second floating diffusionlayer FD₂) of the reset transistor TR2 _(rst). In addition, onesource/drain region is connected to the power source V_(DD).

The selection transistor TR2 _(sel) includes a gate portion, a channelformation region, and source/drain regions. The gate portion isconnected to a selection line SEL₂. In addition, one source/rain regionshares the region with the other source/drain region included in theamplification transistor TR2 _(amp), and the other source/drain regionis connected to a signal line (data output line) VSL₂.

The third imaging element includes an n-type semiconductor region 43 asa photoelectric conversion layer provided on the semiconductor substrate70. A gate portion 46 of a transfer transistor TR3 _(trs), is connectedto a transfer gate line TG₃. In addition, a third floating diffusionlayer FD₃ is provided in a region 46C of the semiconductor substrate 70near the gate portion 46 of the transfer transistor TR3 _(trs). Thecharge stored in the n-type semiconductor region 43 is read out to thethird floating diffusion layer FD₃ through a transfer channel 46A formedalong the gate portion 46.

In the third imaging element, a reset transistor TR3 _(rst), anamplification transistor TR3 _(amp), and a selection transistor TR3_(sel) included in the control unit of the third imaging element arefurther provided on the first surface side of the semiconductorsubstrate 70.

The reset transistor TR3 _(rst) includes a gate portion, a channelformation region, and source/drain regions. The gate portion of thereset transistor TR3 _(rst) is connected to a reset line RST₃. Onesource/drain region of the reset transistor TR3 _(rst) is connected tothe power source

The other source/drain region also serves as the third floatingdiffusion layer FD₃.

The amplification transistor TR3 _(amp) includes a gate portion, achannel formation region, and source/drain regions. The gate portion isconnected to the other source/drain region (third floating diffusionlayer FD₃) of the reset transistor TR3 _(rst). In addition, onesource/drain region is connected to the power source V_(DD).

The selection transistor TR3 _(sel) includes a gate portion, a channelformation region, and source/drain regions. The gate portion isconnected to a selection line SEL₃. In addition, one source/drain regionshares the region with the other source/drain region included in theamplification transistor TR3 _(amp), and the other source/drain regionis connected to a signal line (data output line) VSL₃.

The reset lines RST₁, RST₂, and RST₃ the selection lines SEL₁, SEL₂, andSEL₃, and the transfer gate lines TG₂ and TG₃ are connected to thevertical drive circuit 112 included in the drive circuit. The signallines (data output lines) VSL₁, VSL₂, and VSL₃ are connected to a columnsignal processing circuit 113 included in the drive circuit.

A p⁺ layer 44 is provided between the n-type semiconductor region 43 andthe front surface 70A of the semiconductor substrate 70 to suppressgeneration of dark current. A p⁺ layer 42 is formed between the n-typesemiconductor region 41 and the n-type semiconductor region 43, andfurthermore, part of the side surface of the n-type semiconductor region43 is surrounded by the p⁺ layer 42. A p⁺ layer 73 is formed on the sideof a back surface 70B of the semiconductor substrate 70, and a HfO₂ film74 and an insulating material film 75 include the p⁺ layer 73 to a partwhere the contact hole portion 61 inside of the semiconductor substrate70 is to be formed. In the interlayer insulating layer 76, wires areformed across a plurality of layers that are not illustrated.

The HfO₂ film 74 is a film with negative fixed charge, and the film canbe provided to suppress the generation of dark current. In place of theHfO₂ film, an aluminum oxide (Al₂O₃) film, a zirconium oxide (ZrO₂)film, a tantalum oxide (Ta₂O₃) film, a titanium oxide (TiO₂) film, alanthanum oxide (La₂O₃) film, a praseodymium oxide (Pr₂O₃) film, acerium oxide (CeO₂) film, a neodymium oxide (Nd₂O₃) film, a promethiumoxide (Pm₂O₃) film, a samarium oxide (Sm₂O₃) film, an europium oxide(Eu₂O₃) film, a gadolinium oxide ((Gd₂O₃) film, a terbium oxide (Tb₂O₃)film, a dysprosium oxide (Dy₂O₃) film, a holmium oxide (Ho₂O₃) film, athulium oxide (Tm₂O₃) film, an ytterbium oxide rib₂O₃) film, a lutetiumoxide (1u₂O₃) film, an yttrium oxide (Y₂O₃) film, a hafnium nitridefilm, an aluminum nitride film, a hafnium oxynitride film, or analuminum oxynitride film can also be used. Examples of a depositionmethod of these films include a CVD method, a PVD method, and an AIDmethod.

Hereinafter, an operation of the stacked imaging element (first imagingelement) including the charge storage electrode of Embodiment 1 will bedescribed with reference to FIGS. 5 and 6A. Here, the potential of thefirst electrode 21 is higher than the potential of the second electrode22. That is, for example, the first electrode 21 is set to a positivepotential, and the second electrode 22 is set to a negative potentialElectrons generated by the photoelectric conversion in the photoelectricconversion layer 23A are read out to the floating diffusion layer. Thissimilarly applies to other Embodiments.

The signs used in FIG. 5, FIGS. 20 and 21 in Embodiment 4 describedlater, and FIGS. 32 and 33 in Embodiment 6 are as follows.

P_(A) Potential at a point P_(A) of the inorganic oxide semiconductormaterial layer 23B facing a region positioned in the middle of thecharge storage electrode 24 and the first electrode 21 or in the middleof a transfer control electrode (charge transfer electrode) 25 and thefirst electrode 21 P_(B) Potential at a point P_(B) of the region of theinorganic oxide semiconductor material layer 23B facing the chargestorage electrode 24 P_(C1) Potential at a point P_(C1) of the region ofthe inorganic oxide semiconductor material layer 23B facing a chargestorage electrode segment 24A P_(C3) Potential at a point P_(C3) of theregion of the inorganic oxide semiconductor material layer 23B facing acharge storage electrode segment 24C P_(D) Potential at a point P_(D) ofthe region of the inorganic oxide semiconductor material layer 23Bfacing a transfer control electrode (charge transfer electrode) 25 FDPotential of the first floating diffusion layer FD₁ V_(OA) Potential ofthe charge storage electrode 24 V_(OA-A) Potential of the charge storageelectrode segment 24A V_(OA-B) Potential of the charge storage electrodesegment 24B V_(OA-C) Potential of the charge storage electrode segment24C V_(OT) Potential of the transfer control electrode (charge transferelectrode) 25 RST Potential of the gate portion 51 of the resettransistor TR1_(rst) V_(DD) Potential of the power source VSL₁ Signalline (data output line) VSL₁ TR1_(rst) Reset transistor TR1_(rst)TR1_(amp) Amplification transistor TR1_(amp) TR1_(sel) Selectiontransistor TR1_(sel)

In a charge storage period, the drive circuit applies a potential V₁₁ tothe first electrode 21 and applies a potential V₁₂ to the charge storageelectrode 24. The light incident on the photoelectric conversion layer23A causes photoelectric conversion in the photoelectric conversionlayer 23A. Electron holes generated by the photoelectric conversion aresent from the second electrode 22 to the drive circuit through a wireyou. On the other hand, the potential of the first electrode 21 ishigher than the potential of the second electrode 22. That is, forexample, a positive potential is applied to the first electrode 21, anda negative potential is applied to the second electrode 22. Therefore,the potentials are set so that V₁₂≥V₁₁, preferably, V₁₂>V₁₁, holds. As aresult, the electrons generated by the photoelectric conversion areattracted to the charge storage electrode 24, and the electrons stop atthe inorganic oxide semiconductor material layer 23B facing the chargestorage electrode 24 or in a region of the inorganic oxide semiconductormaterial layer 23B and the photoelectric conversion layer 23A(hereinafter, they will be collectively referred to as “inorganic oxidesemiconductor material layer 23B and the like”). That is, the charge isstored in the inorganic oxide semiconductor material layer 23B and thelike V₁₁ is greater than V₁₁, and therefore, the electrons generatedinside of the photoelectric conversion layer 23A do not move toward thefirst electrode 21. In the time course of the photoelectric conversion,the potential in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24becomes a more negative value.

A reset operation is performed later in the charge storage period. Thisresets the potential of the first floating diffusion layer FD₁, and thepotential of the first floating diffusion layer FD₁ shifts to thepotential V_(DD) of the power source.

After the completion of the reset operation, the charge is read out.That is, in a charge transfer period, the drive circuit applies apotential V₂₁ to the first electrode 21 and applies a potential 2 to thecharge storage electrode 24. Here, the potentials are set so thatV₂₂<V₂₁ holds. As a result, the electrons stopped in the region of theinorganic oxide semiconductor material layer 23B and the like facing thecharge storage electrode 24 are read out to the first electrode 21 andfurther to the first floating diffusion layer FD₁. That is, the chargestored in the inorganic oxide semiconductor material layer 23B and thelike is read out to the control unit.

This completes the series of operations including the charge storage,the reset operation, and the charge transfer.

The operations of the amplification transistor TR1 _(amp) and theselection transistor TR1 _(sel) after the electrons are read out to thefirst floating diffusion layer FD₁ are the same as the operations oftransistors in the past. In addition, the series of operations includingthe charge storage, the reset operation, and the charge transfer of thesecond imaging element and the third imaging element are similar to theseries of operations including the charge storage, the reset operation,and the charge transfer in the past. In addition, the reset noise of thefirst floating diffusion layer FD₁ can be removed in a correlated doublesampling (GDS) process as in a technique in the past.

As described, the charge storage electrode arranged apart from the firstelectrode and arranged to face the photoelectric conversion layerthrough the insulating layer is provided in Embodiment 1. Therefore, inthe photoelectric conversion layer after the light is applied to thephotoelectric conversion layer, a kind of capacitor is formed by theinorganic oxide semiconductor material layer and the like, theinsulating layer, and the charge storage electrode. The charge can bestored in the inorganic oxide semiconductor material layer and the like.Therefore, the charge storage portion can be fully depleted to deletethe charge at the start of exposure. This can suppress the phenomenon ofreduction in image quality caused by the degradation of random noise dueto an increase in kTC noise. In addition, all pixels can be reset atonce, and a so-called global shutter function can be realized.

FIG. 79 illustrates a conceptual diagram of the solid-state imagingapparatus of Embodiment 1. A solid-state imaging apparatus 100 ofEmbodiment 1 includes an imaging region 111 including stacked imagingelements 101 arranged in a two-dimensional array, the vertical drivecircuit 112 as a drive circuit (peripheral circuit) of the stackedimaging elements 101, the column signal processing circuit 113, ahorizontal drive circuit 114, an output circuit 115, a drive controlcircuit 116, and the like. The circuits can include well-known circuits,or other circuit configurations (for example, various circuits used in aCCD imaging apparatus or CMOS imaging apparatus in the past) can beobviously used to provide the circuits. In FIG. 79, reference number“101” is displayed in only one line of the stacked imaging elements 101.

The drive control circuit 116 generates a clock signal and a controlsignal as references for the operation of the vertical drive circuit112, the column signal processing circuit 113, and the horizontal drivecircuit 114 based on a vertical synchronization signal, a horizontalsynchronization signal, and a master clock. In addition, the generatedclock signal and control signal are input to the vertical drive circuit112, the column signal processing circuit 113, and the horizontal drivecircuit 114.

The vertical drive circuit 112 includes, for example, a shift registerand sequentially selects and scans the stacked imaging elements 101 ofthe imaging region 111 row by row in the vertical direction. Inaddition, a pixel signal (image signal) based on a current (signal)generated according to an amount of light reception in each stackedimaging element 101 is transmitted to the column signal processingcircuit 113 through the signal line (data output line) 117, VSL.

The column signal processing circuit 113 is arranged for, for example,each column of the stacked. imaging elements 101 and is configured touse signals from black reference pixels (although not illustrated,formed around effective pixel regions) to apply, for each imagingelement, signal processing, such as noise removal and signalamplification, to the image signals output from the stacked imagingelements 101 of one line. A horizontal selection switch (notillustrated) is connected and provided between an output stage of thecolumn signal processing circuit 113 and a horizontal signal line 118.

The horizontal drive circuit 114 includes, for example, a shift registerand sequentially outputs horizontal scan pulses to sequentially selectthe column signal processing circuits 113. The horizontal drive circuit114 outputs the signal from each column signal processing circuit 113 tothe horizontal signal line 118.

The output circuit 115 applies signal processing to the signalssequentially supplied from the column signal processing circuits 113through the horizontal signal line 118 and outputs the signals.

FIG. 9 illustrates an equivalent circuit diagram of a modified exampleof the imaging element of Embodiment 1, and FIG. 10 illustrates aschematic layout drawing of the first electrode, the charge storageelectrode, and the transistors included in the control unit. In thisway, the other source/drain region 51B of the reset transistor TR1_(rst) may be grounded, instead of connecting the other source/drainregion 51B to the power source V_(DD).

The imaging element of Embodiment 1 can be produced by, for example, thefollowing method. That is, an SOI substrate is first prepared. A firstsilicon layer is then formed on the surface of the SOI substrate basedon an epitaxial growth method, and the p⁺ layer 73 and the n-typesemiconductor region 41 are formed on the first silicon layer. Next, asecond silicon layer is formed on the first silicon layer based on theepitaxial growth method, and the element separation region 71, the oxidefilm 72, the p⁺ layer 42, the n-type semiconductor region 43, and the p⁺layer 44 are formed on the second silicon layer. In addition, varioustransistors and the like included in the control unit of the imagingelement are formed on the second silicon layer, and the wiring layer 62,the interlayer insulating layer 76, and various wires are further formedon top of that. The interlayer insulating layer 76 and a supportsubstrate (not illustrated) are then pasted together. Subsequently, theSOI substrate is removed to expose the first silicon layer. The surfaceof the second silicon layer corresponds to the front surface 70A of thesemiconductor substrate 70, and the surface of the first silicon layercorresponds to a back surface 70B of the semiconductor substrate 70. Inaddition, the first silicon layer and the second silicon layer arecollectively expressed as the semiconductor substrate 70. Next, anopening portion for forming the contact hole portion 61 is formed on theback surface 70B side of the semiconductor substrate 70, and the HfO₂,film 74, the insulating material film 75, and the contact hole portion61 are formed. Furthermore, the pad portions 63 and 64, the interlayerinsulating layer 81, the connection holes 65 and 66, the first electrode21, the charge storage electrode 24, and the insulating layer 82 areformed. Next, the connection portion 67 is opened, and the inorganicoxide semiconductor material layer 23B, the photoelectric conversionlayer 23A, the second electrode 22, the insulating layer 83, and theon-chip microlens 14 are formed. In this way, the imaging element ofEmbodiment 1 can be obtained.

In addition, although not illustrated, the insulating layer 82 may havea two-layer configuration including an insulating layer/lower layer andan insulating layer/upper layer. That is, the insulating layer/lowerlayer can be formed at least over the charge storage electrode 24 and inthe area between the charge storage electrode 24 and the first electrode21 (more specifically, the insulating layer/lower layer can be formed onthe interlayer insulating layer 81 including the charge storageelectrode 24). A planarization process can be applied to the insulatinglayer/lower layer, and then the insulating layer/upper layer can beformed over the insulating layer/lower layer and the charge storageelectrode 24. As a result, the insulating layer 82 can be certainlyplanarized. Furthermore, the connection portion. 67 is only required tobe opened in the insulating layer 82 obtained in this way.

Embodiment 2

Embodiment 2 is a modification of Embodiment 1. An imaging element ofEmbodiment 2 illustrated in a schematic partial cross-sectional view ofFIG. 11 is a front illuminated type imaging element. The imaging elementhas a stacked structure of three imaging elements including: a greenlight imaging element of first type in Embodiment 1 (first imagingelement) sensitive to green the green light imaging element including agreen light photoelectric conversion layer of first type for absorbinggreen light; a blue light imaging element in the past of second type(second imaging element) sensitive to blue light, the blue light imagingelement including a blue light photoelectric conversion layer of secondtype for absorbing blue light; and a red light imaging element in thepast of second type (third imaging element) sensitive to red light, thered light imaging element including a red light photoelectric conversionlayer of second type for absorbing red light. Here, the red lightimaging element (third imaging element) and the blue light imagingelement (second imaging element) are provided in the semiconductorsubstrate 70, and the second imaging element is positioned on the lightincident side with respect to the third imaging element. In addition,the green light imaging element (first imaging element) is provided. onthe upper side of the blue light imaging element (second imagingelement).

Various transistors included. In the control unit are provided. On thefront surface 70A side of the semiconductor substrate 70 as inEmbodiment 1. The transistors can have configurations and structuressubstantially similar to the transistors described in Embodiment 1. Inaddition, the second imaging element and the third imaging element areprovided on the semiconductor substrate 70, and the imaging elements canalso have configurations and structures substantially similar to thesecond imaging element and the third imaging element described inEmbodiment 1.

The interlayer insulating layer 81 is formed on the upper side of thefront surface 70A of the semiconductor substrate 70, and thephotoelectric conversion unit (first electrode 21, inorganic oxidesemiconductor material layer 23B, photoelectric conversion layer 23A,second electrode 22, charge storage electrode 24, and the like)including the charge storage electrode included in the imaging elementof Embodiment 1 is provided on the upper side of the interlayerinsulating layer 81.

In this way, the configuration and the structure of the imaging elementof Embodiment 2 can be similar to the configuration and the structure ofthe imaging element of Embodiment 1 except that the imaging element ofEmbodiment 2 is a front illuminated type. Therefore, the details willnot be described.

Embodiment 3

Embodiment 3 is a modification of Embodiment 1 and Embodiment 2.

An imaging element of Embodiment 3 illustrated in a schematic partialcross-sectional view of FIG. 12 is a back illuminated type imagingelement. The imaging element has a stacked structure of two imagingelements including the first imaging element of first type in Embodiment1 and the second imaging element of second type. In addition, a modifiedexample of the imaging element of Embodiment 3 illustrated in aschematic partial cross-sectional view of FIG. 13 provides a frontilluminated type imaging element. The imaging element has a stackedstructure of two imaging elements including the first imaging element offirst type in Embodiment 1 and the second imaging element of secondtype. Here, the first imaging element absorbs light of primary colors,and the second imaging element absorbs light of complementary colors.Alternatively, the first imaging element absorbs white light, and thesecond imaging element absorbs infrared rays.

A modified example of the imaging element of Embodiment 3 illustrated ina schematic partial cross-sectional view of FIG. 14 is a backilluminated type imaging element. The imaging element includes the firstimaging element of first type in Embodiment 1. In addition, a modifiedexample of the imaging element of Embodiment 3 illustrated in aschematic partial cross-sectional view of FIG. 15 is a front illuminatedtype imagining element. The imaging element includes the first imagingelement of first type in Embodiment 1. Here, the first imaging elementincludes three types of imaging elements including an imaging elementthat absorbs red light, an imaging element that absorbs green light, andan imaging element that absorbs blue light. Furthermore, the pluralityof imaging elements are included in the solid-state imaging apparatusaccording to the first aspect of the present disclosure. An example ofthe arrangement of the plurality of imaging elements includes a Bayerarray. Color filter layers for separating blue, green, and red arearranged on the light incident side of the imaging elements asnecessary.

Instead of providing one photoelectric conversion unit including thecharge storage electrode of first type in Embodiment 1, twophotoelectric conversion units can be stacked (that is, twophotoelectric conversion units including the charge storage electrodesare stacked, and a control unit of the two photoelectric conversionunits is provided. On the semiconductor substrate), or threephotoelectric conversion units can be stacked (that is, threephotoelectric conversion units including the charge storage electrodesare stacked, and a control unit of the three photoelectric conversionunits is provided on the semiconductor substrate). The following tableillustrates examples of the stacked structures of the imaging element offirst type and the imaging element of second type.

First type Second type Back illuminated 1 2 type and front Green Blue +Red illuminated type 1 1 Primary color Complementary color 1 1 WhiteInfrared 1 0 Blue, Green, or Red 2 2 Green + Infrared Blue + Red 2 1Green + Blue Red 2 0 White + Infrared 3 2 Green + Blue + Red Blue-Green(Emerald) + Infrared 3 1 Green + Blue + Red Infrared 3 0 Blue + Green +Red

Embodiment 4

Embodiment 4 is a modification of Embodiments 1 to 3, and Embodiment 4relates to an imaging element and the like including a transfer controlelectrode (charge transfer electrode) of the present disclosure. FIG. 16illustrates a schematic partial cross-sectional view of part of theimaging element of Embodiment 4. FIGS. 17 and 18 illustrate equivalentcircuit diagrams of the imaging element of Embodiment 4. FIG. 19illustrates a schematic layout drawing of the first electrode, thetransfer control electrode, and the charge storage electrode included inthe photoelectric conversion unit and the transistors of the controlunit included in the imaging element of Embodiment 4. FIGS. 20 and 21schematically illustrate the state of potential in each section duringoperation of the imaging element of Embodiment 4. FIG. 6B illustrates anequivalent circuit diagram for describing each section of the imagingelement of Embodiment 4. In addition, FIG. 22 illustrates a schematiclayout drawing of the first electrode, the transfer control electrode,and the charge storage electrode included in the photoelectricconversion unit of the imaging element of Embodiment 4. FIG. 23illustrates a schematic perspective view of the first electrode, thetransfer control electrode, the charge storage electrode, the secondelectrode, and the contact hole portion.

The imaging element of Embodiment 4 further includes a transfer controlelectrode (charge transfer electrode) 25 arranged between the firstelectrode 21 and the charge storage electrode 24, arranged apart fromthe first electrode 21 and the charge storage electrode 24, and arrangedto face the inorganic oxide semiconductor material layer 23B through theinsulating layer 82. The transfer control electrode 25 is connected tothe pixel drive circuit included in the drive circuit through aconnection hole 68B and a pad portion 68A provided in the interlayerinsulating layer 81 and through the wire V_(CT). Note that variousconstituent elements of the imaging element positioned on the lower sideof the interlayer insulating layer 81 are collectively indicated byreference number 13 for convenience in order to simplify the drawings.

Hereinafter, an operation of the imaging element (first imaging element)of Embodiment 4 will be described with reference to FIGS. 20 and 21.Note that the values of the potential applied to the charge storageelectrode 24 and the potential at the point P_(D) particularly varybetween FIGS. 20 and 21.

In the charge storage period, the drive circuit applies the potentialV₁₁ to the first electrode 21, applies the potential V₁₂ to the chargestorage electrode 24, and applies a potential V₁₃ to the transfercontrol electrode 25. The light incident on the photoelectric conversionlayer 23A causes photoelectric conversion in the photoelectricconversion layer 23A. The electron holes generated by the photoelectricconversion are sent from the second electrode 22 to the drive circuitthrough the wire V_(OU). On the other hand, the potential of the firstelectrode 21 is higher than the potential of the second electrode 22.That is, for example, a positive potential is applied to the firstelectrode 21, and a negative potential is applied to the secondelectrode 22. Therefore, the potentials are set so that V₁₂>V₁₃ (forexample, V₁₂>V₁₁>V₁₃ or V₁₁>V₁₂>V₁₃) holds. As a result, the electronsgenerated by the photoelectric conversion are attracted to the chargestorage electrode 24, and the electrons stop in the region of theinorganic oxide semiconductor material layer 23B and the like facing thecharge storage electrode 24. That is, the charge is stored in theinorganic oxide semiconductor material layer 23B and the like. V₁₂ isgreater than V₁₃, and this can certainly prevent the movement of theelectrons generated inside of the photoelectric conversion layer 23Atoward the first electrode 21. In the time course of the photoelectricconversion, the potential in the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 becomes a more negative value.

The reset operation is performed later in the charge storage period.This resets the potential of the first floating diffusion layer FD₁, andthe potential of the first floating diffusion layer FD₁ shifts to thepotential V_(DD) of the power source.

After the completion of the reset operation, the charge is read out.That is, in the charge transfer period, the drive circuit applies thepotential V₂₁ to the first electrode 21, applies the potential V₂₂ tothe charge storage electrode 24, and applies a potential V₂₃ to thetransfer control electrode 25. Here, the potentials are set so thatV₂₂≥V₂₃≥V₂₁ (preferably, V₂₂<V₂₃<V₂₁) holds. In a case where thepotential V₁₃ is applied to the transfer control electrode 25, thepotentials are only required to be set so that V₂₂≥V₁₃≥V₂₁ (preferably,V₂₂<V₁₃<V₂₁) holds. As a result, the electrons stopped in the region ofthe inorganic oxide semiconductor material layer 23B and the like facingthe charge storage electrode 24 are certainly read out to the firstelectrode 21 and further to the first floating diffusion layer FD₁. Thatis, the charge stored in the inorganic oxide semiconductor materiallayer 23B and the lake is read out to the control unit.

This completes the series of operations including the charge storage,the reset operation, and the charge transfer.

The operations of the amplification transistor TR1 _(amp) and theselection transistor TR1 _(sel) after the electrons are read out to thefirst floating diffusion layer FD₁ are the same as the operations oftransistors in the past. In addition, for example, the series ofoperations including the charge storage, the reset operation, and thecharge transfer of the second imaging element and the third imagingelement are similar to the series of operations including the chargestorage, the reset operation, and the charge transfer in the past.

As in FIG. 24 illustrating a schematic layout drawing of the firstelectrode, the charge storage electrode, and the transistors of thecontrol unit included in the modified example of the imaging element ofEmbodiment 4, the other source/drain region 51B of the reset transistorTR1 _(rst) may be grounded, instead of connecting the other source/drainregion 51B to the power source V_(DD).

Embodiment 5

Embodiment 5 is a modification of Embodiments 1 to 4, and Embodiment 5relates to an imaging element and the like including a dischargeelectrode of the present disclosure. FIG. 25 illustrates a schematicpartial cross-sectional view of part of the imaging element ofEmbodiment 5. FIG. 26 illustrates a schematic layout drawing of thefirst electrode, the charge storage electrode, and the dischargeelectrode included in the photoelectric conversion unit including thecharge storage electrode of the imaging element of Embodiment 5. FIG. 27illustrates a schematic perspective view of the first electrode, thecharge storage electrode, the discharge electrode, the second electrode,and the contact hole portion.

The imaging element of Embodiment 5 further includes a dischargeelectrode 26 connected to the inorganic oxide semiconductor materiallayer 23B through a connection portion 69 and arranged apart from thefirst electrode 21 and the charge storage electrode 24. Here, thedischarge electrode 26 is arranged to surround the first electrode 21and the charge storage electrode 24 (that is, in a frame shape). Thedischarge electrode 26 is connected to the pixel drive circuit includedin the drive circuit. The inorganic oxide semiconductor material layer23B extends in the connection portion 69. That is, the inorganic oxidesemiconductor material layer 23B extends in a second opening portion 86provided in the insulating layer 82 and is connected to the dischargeelectrode 26. The discharge electrode 26 is shared (standardized) by aplurality of imaging elements.

In Embodiment 5, the drive circuit applies the potential V₁₁ to thefirst electrode 21, applies the potential V₁₂ to the charge storageelectrode 24, and applies a potential V₁₄ to the discharge electrode 26in the charge storage period. The charge is stored in the inorganicoxide semiconductor material layer 23B and the like. The light incidenton the photoelectric conversion layer 23A causes photoelectricconversion in the photoelectric conversion layer 23A. The electron holesgenerated by the photoelectric conversion are sent from the secondelectrode 22 to the drive circuit through the wire V_(OU). On the otherhand, the potential of the first electrode 21 is higher than thepotential of the second electrode 22. That is, for example, a positivepotential is applied to the first electrode 21, and a negative potentialis applied to the second electrode 22. Therefore, the potentials are setso that V₁₄>V₁₁ (for example, V₁₂>V₁₄>V₁₀ holds. As a result, theelectrons generated by the photoelectric conversion are attracted to thecharge storage electrode 24, and the electrons stop in the region of theinorganic oxide semiconductor material layer 23B and the like facing thecharge storage electrode 24. This can certainly prevent the movement ofthe electrons toward the first electrode 21. However, the electrons notsufficiently attracted to the charge storage electrode 24, or theelectrons not completely stored in the inorganic oxide semiconductormaterial layer 23B and the like (so-called overflown electrons) are sentto the drive circuit through the discharge electrode 26.

The reset operation is performed later in the charge storage period.This resets the potential of the first floating diffusion layer FD₁, andthe potential of the first floating diffusion layer FD₁ shifts to thepotential V_(DD) of the power source.

After the completion of the reset operation, the charge is read out.That is, in the charge transfer period, the drive circuit applies thepotential V₂₁ to the first electrode 21, applies the potential V₂₂ tothe charge storage electrode 24, and applies a potential V₂₄ to thedischarge electrode 26. Here, the potentials are set so that V₂₄<V₂₁(for example, V₂₄<V₂₂<V₂₁) holds. As a result, the electrons stopped inthe region of the inorganic oxide semiconductor material layer 23B andthe like facing the charge storage electrode 24 are certainly read outto the first electrode 21 and further to the first floating diffusionlayer FD₁. That is, the charge stored in the inorganic oxidesemiconductor material layer 23B and the like is read out to the controlunit.

This completes the series of operations including the charge storage,the reset operation, and the charge transfer.

The operations of the amplification transistor TR1 _(amp) and theselection transistor TP1 _(sel) after the electrons are read out to thefirst floating diffusion layer FD₁ are the same as the operations oftransistors in the past. In addition, for example, the series ofoperations including the charge storage, the reset operation, and thecharge transfer of the second imaging element and the third imagingelement are similar to the series of operations including the chargestorage, the reset operation, and the charge transfer in the past.

In Embodiment 5, the so-called overflown electrons are sent to the drivecircuit through the discharge electrode 26. Therefore, leakage of theelectrons to charge storage portions of adjacent pixels can besuppressed, and blooming can be suppressed. This can also improve theimaging performance of the imaging element.

Embodiment 6

Embodiment 6 is a modification of Embodiments 1 to 5, and Embodiment 6relates to an imaging element and the like including a plurality ofcharge storage electrode segments of the present disclosure.

FIG. 28 illustrate a schematic partial cross-sectional view of part ofthe imaging element of Embodiment 6. FIGS. 29 and 30 illustrate anequivalent circuit diagram of the imaging element of Embodiment 6. FIG.31 illustrates a schematic layout drawing of the first electrode and thecharge storage electrode included in the photoelectric conversion unitincluding the charge storage electrode and the transistors of thecontrol unit included in the imaging element of Embodiment 6. FIGS. 32and 33 schematically illustrate the state of potential in each sectionduring operation of the imaging element of Embodiment 6. FIG. 6Cillustrates an equivalent circuit diagram for describing each section ofthe imaging element of Embodiment 6. In addition, FIG. 34 illustrates aschematic layout drawing of the first electrode and the charge storageelectrode included in the photoelectric conversion unit including thecharge storage electrode of the imaging element of Embodiment 6. FIG. 35illustrates a schematic perspective view of the first electrode, thecharge storage electrode, the second electrode, and the contact holeportion.

In Embodiment 6, the charge storage electrode 24 includes the pluralityof charge storage electrode segments 24A, 24B, and 24C. The number ofcharge storage electrode segments can be equal to or greater than 2, andthe number is “3” in embodiment 6. In addition, the potential of thefirst electrode 21 is higher than the potential of the second electrode22 in the imaging element of Embodiment 6. That is, for example, apositive potential is applied to the first electrode 21, and a negativepotential is applied to the second electrode 22. Furthermore, in thecharge transfer period, the potential applied to the charge storageelectrode segment 24A positioned at a place closest to the firstelectrode 21 is higher than the potential applied to the charge storageelectrode segment 24C positioned at a place farthest from the firstelectrode 21. In this way, a potential gradient is provided to thecharge storage electrode 24. That is, the electrons stopped in theregion of the inorganic oxide semiconductor material layer 23B and thelike facing the charge storage electrode 24 are more certainly read outto the first electrode 21 and further to the first floating diffusionlayer FD₁. That is, the charge stored in the inorganic oxidesemiconductor material layer 231B and the like is read out to thecontrol unit.

In the example illustrated in FIG. 32, the potential of the chargestorage electrode segment 24C<the potential of the charge storageelectrode segment 24B<the potential of the charge storage electrodesegment. 24A holds in the charge transfer period. In this way, theelectrons stopped in the region of the inorganic oxide semiconductormaterial layer 23B and the like are read out to the first floatingdiffusion layer FD₁ all at once. On the other hand, in the exampleillustrated in FIG. 33, the potential of the charge storage electrodesegment 240, the potential of the charge storage electrode segment 24B,and the potential of the charge storage electrode segment 24A aregradually changed (that is, changed step-wise or in a slope shape) inthe charge transfer period. In this way, the electrons stopped in theregion of the inorganic oxide semiconductor material layer 23B and thelike facing the charge storage electrode segment 240 are moved to theregion of the inorganic oxide semiconductor material layer 23B and thelike facing the charge storage electrode segment 24B. Then, theelectrons stopped in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrodesegment 241B are moved to the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode segment 24A. Then, the electrons stopped in the region of theinorganic oxide semiconductor material layer 23B and the like facing thecharge storage electrode segment 24A are certainly read out to the firstfloating diffusion layer FD₁.

As in FIG. 36 illustrating a schematic layout drawing of the firstelectrode, the charge storage electrode, and the transistors of thecontrol unit included in the modified example of the imaging element ofEmbodiment 6, the other source/drain region 51B of the reset transistorTR1 _(rst) may be grounded, instead of connecting the other source/drainregion 51B to the power source V_(DD).

Embodiment 7

Embodiment 7 is a modification of Embodiments 1 to 6, and Embodiment 7relates to the imaging elements of the first configuration and the sixthconfiguration.

FIG. 37 illustrates a schematic partial cross-sectional view of theimaging element of Embodiment 7. FIG. 38 illustrates an enlargedschematic partial cross-sectional view of the part where the chargestorage electrode, the inorganic oxide semiconductor material layer, thephotoelectric conversion layer, and the second electrode are stacked.The equivalent circuit diagram of the imaging element of Embodiment 7 issimilar to the equivalent circuit diagram of the imaging element ofEmbodiment 1 described in FIGS. 2 and 3. The schematic layout drawing ofthe first electrode and the charge storage electrode included in thephotoelectric conversion unit including the charge storage electrode andthe transistors of the control unit included in the imaging element ofEmbodiment 7 is similar to the imaging element of Embodiment 1 describedin FIG. 4. Furthermore, the operation of the imaging element (firstimaging element) of Embodiment 7 is substantially similar to theoperation of the imaging element of Embodiment 1.

Here, in the imaging element of Embodiment 7 or imaging elements ofEmbodiments 8 to 12 described later, the photoelectric conversion unitincludes N (where N≥2) photoelectric conversion unit segments(specifically, three photoelectric conversion unit segments 10′₁, 10′₂,and 10′₃), the inorganic oxide semiconductor material layer 23B and thephotoelectric conversion layer 23A include N photoelectric conversionlayer segments (specifically, three photoelectric conversion layersegments 23′₁, 23′₂, and 23′₃) and

the insulating layer 82 includes N insulating layer segments(specifically, three insulating layer segments 82′₁, 82′₂, and 82′₃).

In Embodiments 7 to 9, the charge storage electrode 24 includes N chargestorage electrode segments (specifically, three charge storage electrodesegments 24′₃, 24′₂, and 24′₃ in each Embodiment).

In Embodiments 10 and 11 and in Embodiment 9 depending on the case, thecharge storage electrode 24 includes N charge storage electrode segments(specifically, three charge storage electrode segments 24′₁, 24′₂, and24′₃) arranged apart from each other, an nth (where, n=1, 2, 3 . . . N)photoelectric conversion unit segment 10′_(n) includes an nth chargestorage electrode segment 24′_(n), an nth insulating layer segment82′_(n), and an nth photoelectric conversion layer segment 23′_(n), and

the larger the value of n of the photoelectric conversion unit segment,the farther the position of the photoelectric conversion unit segmentfrom the first electrode 21. Here, the photoelectric conversion layersegments 23′₁, 23′₂, and 23′ denote segments in which the photoelectricconversion layers and the inorganic oxide semiconductor material layersare stacked, and in the drawings, the segment is expressed by one layerfor the simplification of the drawings. This similarly applies to thefollowing description.

Note that in the photoelectric conversion layer segment, the thicknessof the part of the photoelectric conversion layer may be changed, andthe thickness of the part of the inorganic oxide semiconductor materiallayer may be maintained to change the thickness of the photoelectricconversion layer segment. The thickness of the part of the photoelectricconversion layer may be maintained, and the thickness of the part of theinorganic oxide semiconductor material layer may be changed to changethe thickness of the photoelectric conversion layer segment. Thethickness of the part of the photoelectric conversion layer may bechanged, and the thickness of the part of the inorganic oxidesemiconductor material layer may be changed to change the thickness ofthe photoelectric conversion layer segment.

Alternatively, the imaging element of Embodiment 7 or the imagingelements of Embodiments 8 and 11 described later include

a photoelectric conversion unit including the first electrode 21, theinorganic oxide semiconductor material layer 23B, the photoelectricconversion layer 23A, and the second electrode 22 that are stacked, inwhich the photoelectric conversion unit further includes the chargestorage electrode 24 arranged apart from the first electrode 21 andarranged to face the inorganic oxide semiconductor material layer 23Bthrough the insulating layer 82, and

the cross-sectional area of the stacked part of the charge storageelectrode 24, the insulating layer 82, the inorganic oxide semiconductormaterial layer 23B, and the photoelectric conversion layer 23A when thestacked part is cut in a YZ virtual plane changes in accordance with thedistance from the first electrode, where a Z direction is the stackingdirection of the charge storage electrode 24, the insulating layer 82,the inorganic oxide semiconductor material layer 23B, and thephotoelectric conversion layer 23A, and an X direction is a directionaway from the first electrode 21.

Furthermore, in the imaging element of Embodiment 7, the thicknesses ofthe insulating layer segments gradually change from the firstphotoelectric conversion unit segment 10′₁ to an Nth photoelectricconversion unit segment 10′_(N). Specifically, the thicknesses of theinsulating layer segments gradually increase. Alternatively, in theimaging element of Embodiment 7, the width of the cross section of thestacked part is constant, and the thickness of the cross section of thestacked part, specifically, the thickness of the insulating layersegment, gradually increases in accordance with the distance from thefirst electrode 21. Note that the thicknesses of the insulating layersegments increase step-wise. The thickness of the insulating layersegment 82′_(n) in the nth photoelectric conversion unit segment 10′_(n)is constant. Assuming that the thickness of the insulating layer segment82′_(n) in the nth photoelectric conversion unit segment 10′_(n) is “1,”the thickness of an insulating layer segment 82′_((n+1)) in an (n+1)thphotoelectric conversion unit segment 10′_((n+1)) can be 2 to 10.However, the values are not limited to these, in Embodiment 7, thethicknesses of the charge storage electrode segments 24′₁, 24′₂, and24′₃ are gradually reduced to gradually increase the thicknesses of theinsulating layer segments 82′₁, 82′₂, and 82′₃. The thicknesses of thephotoelectric conversion layer segments 23′₁, 23′₂, and 23′₃ areconstant.

Hereinafter, an operation of the imaging element of Embodiment 7 will bedescribed.

In the charge storage period, the drive circuit applies the potential tothe first electrode 21 and applies the potential V₁₂ to the chargestorage electrode 24. The light incident on the photoelectric conversionlayer 23A causes photoelectric conversion in the photoelectricconversion layer 23A. The electron holes generated by the photoelectricconversion are sent from the second electrode 22 to the drive circuitthrough the wire V_(OU). On the other hand, the potential of the firstelectrode 21 is higher than the potential of the second electrode 22.That is, for example, a positive potential is applied to the firstelectrode 21, and a negative potential is applied to the secondelectrode 22. Therefore, the potentials are set so that V₁₂≥V₁₁,preferably, V₁₂>V₁₁, holds. As a result, the electrons generated by thephotoelectric conversion are attracted to the charge storage electrode24, and the electrons stop in the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24. That is, the charge is stored in the inorganic oxidesemiconductor material layer 23B and the like. V₁₂ is greater than V₁₁,and therefore, the electrons generated inside of the photoelectricconversion layer 232 do not move toward the first electrode 21. In thetime course of the photoelectric conversion, the potential in the regionof the inorganic oxide semiconductor material layer 23B and the likefacing the charge storage electrode 24 becomes a more negative value.

In the configuration adopted in the imaging element of Embodiment 7, thethicknesses of the insulating layer segments gradually increase.Therefore, when the state shifts to V₁₂>V₁₁ in the charge storageperiod, the nth photoelectric conversion unit segment. 10′_(n) can storemore charge than the (n+1)th photoelectric conversion unit segment10′_((n+1)). A strong electric field is also applied, and the flow ofcharge from the first photoelectric conversion unit segment 10′₁ to thefirst electrode 21 can be certainly prevented.

The reset operation is performed later in the charge storage period.This resets the potential of the first floating diffusion layer FD₁, andthe potential of the first floating diffusion layer FD₁ shifts to thepotential V_(DD) of the power source.

After the completion of the reset operation, the charge is read out.That is, in the charge transfer period, the drive circuit applies thepotential 21 to the first electrode 21 and applies the potential V₂₂ tothe charge storage electrode 24. Here, the potentials are set so thatV₂₁>V₂₂ holds. As a result, the electrons stopped in the region of theinorganic oxide semiconductor material layer 23B and the like facing thecharge storage electrode 24 are read out to the first electrode 21 andfurther to the first floating diffusion layer FD₁. That is, the chargestored in the inorganic oxide semiconductor material layer 23B and thelike is read out to the control unit.

More specifically, when the state shifts to V₂₁>V₂₂ in the chargetransfer period, the flow of charge from the first photoelectricconversion unit segment 10′₁ to the first electrode 21 and the flow ofcharge from the (n+1) th photoelectric conversion unit segment10′_((n+)1) to the nth photoelectric conversion unit segment 10′_(n) canbe certainly secured.

This completes the series of operations including the charge storage,the reset operation, and the charge transfer.

In the imaging element of Embodiment 7, the thicknesses of theinsulating layer segments gradually change from the first photoelectricconversion unit segment to the Nth photoelectric conversion unitsegment. Alternatively, the cross-sectional area of the stacked part ofthe charge storage electrode, the insulating layer, the inorganic oxidesemiconductor material layer, and the photoelectric conversion layerwhen the stacked part is cut in the YZ virtual plane changes inaccordance with the distance from the first electrode. Therefore, a kindof charge transfer gradient is formed, and the charge generated by thephotoelectric conversion can be more easily and certainly transferred.

The imaging element of Embodiment 7 can be produced by a methodsubstantially similar to the imaging element of Embodiment 1, and thedetails will not be described.

Note that in forming the first electrode 21, the charge storageelectrode 24, and the insulating layer 82 in the imaging element ofEmbodiment 7, a conductive material layer for forming the charge storageelectrode 24′₃ is deposited on the interlayer insulating layer 81 first.The conductive material layer is patterned, and the conductive materiallayer is left is the region where the photoelectric conversion unitsegments 10′₁, 10′₂, and 10′₃ and the first electrode 21 are to beformed. In this way, part of the first electrode 21 and the chargestorage electrode 24′₃ can be obtained. Next, an insulating layer forforming the insulating layer segment 82′₃ is deposited on the entiresurface. The insulating layer is patterned, and a planarization processis executed. In this way, the insulating layer segment 82′₃ can beobtained. Next, a conductive material layer for forming the chargestorage electrode 24′₂ is deposited on the entire surface, and theconductive material layer is patterned. The conductive material layer isleft in the region where the photoelectric conversion unit segments 10′₁and 10′₂ and the first electrode 21 are to be formed. In this way, partof the first electrode 21 and the charge storage electrode 24′₂ can beobtained. Next, an insulating layer for forming the insulating layersegment 82′₂ is deposited on the entire surface. The insulating layer ispatterned, and a planarization process is executed. In this way, theinsulating layer segment 82′₂ can be obtained. Next, a conductivematerial layer for forming the charge storage electrode 24′₁ isdeposited on the entire surface. The conductive material layer ispatterned, and the conductive material layer is left in the region wherethe photoelectric conversion unit segment 10′₁ and the first electrode21 are to be formed.

In this way, the first electrode 21 and the charge storage electrode24′₁ can be obtained. Next, as insulating layer is deposited on theentire surface, and a planarization process is executed. In this way,the insulating layer segment 82′₁ (insulating layer 82) can be obtained.Furthermore, the inorganic oxide semiconductor material layer 23B andthe photoelectric conversion layer 23A are formed on the insulatinglayer 82. In this way, the photoelectric conversion unit segments 10′₁,10′₂, and 10′₃ can be obtained.

As in FIG. 39 illustrating a schematic layout drawing of the firstelectrode, the charge storage electrode, and the transistors of thecontrol unit included in the modified example of the imaging element ofEmbodiment 7, the other source/drain region 51B of the reset transistorTR1 _(rst) may be grounded, instead of connecting the other source/drainregion 51B to the power source V_(DD).

Embodiment 8

An imaging element of Embodiment 8 relates to the imaging elements ofthe second configuration and the sixth configuration of the presentdisclosure. As in FIG. 40 illustrating an enlarged schematic partialcross-sectional view of the part in which the charge storage electrode,the inorganic oxide semiconductor material layer, the photoelectricconversion layer, and the second electrode are stacked, the thicknessesof the photoelectric conversion layer segments gradually change from thefirst photoelectric conversion unit segment 10′₁ to the Nthphotoelectric conversion unit segment 10′_(N) in the imaging element ofEmbodiment 8. Alternatively, in the imaging element of Embodiment 8, thewidths of the cross sections of the stacked parts are constant, and thethicknesses of the cross sections of the stacked parts, specifically,the thicknesses of the photoelectric conversion layer segments,gradually increase in accordance with the distance from the firstelectrode 21. More specifically, the thicknesses of the photoelectricconversion layer segments gradually increase. Note that the thicknessesof the photoelectric conversion layer segments increase step-wise. Thethickness of the photoelectric conversion layer segment 23′_(n) in thenth photoelectric conversion unit segment 10′_(n) is constant. Assumingthat the thickness of the photoelectric conversion layer segment 23′_(n)in the nth photoelectric conversion unit segment 10′_(n) is “1,” thethickness of a photoelectric conversion layer segment 23 _((n+1)) in the(n+1)th photoelectric conversion unit segment 10′_((n+1)) can be 2 to10. However, the values are not limited to these. In Embodiment 8, thethicknesses of the charge storage electrode segments 24′₁, 24′₂, and24′₃ are gradually reduced to gradually increase the thicknesses of thephotoelectric conversion layer segments 23′₁, 23′₂, and 23′₃. Thethicknesses of the insulating layer segments 82′₁, 82′₂, and 82′₃ areconstant. Furthermore, in the photoelectric conversion layer segment,the thickness of the part of the inorganic oxide semiconductor materiallayer can be maintained, and the thickness of the part of thephotoelectric conversion layer can be changed to change the thickness ofthe photoelectric conversion layer segment, for example.

In the imaging element of Embodiment 8, the thicknesses of thephotoelectric conversion layer segments gradually increase. Therefore,when the state shifts to V₁₂≥V₁₁ in the charge storage period, astronger electric field is applied to the nth photoelectric conversionunit segment 10′_(n) than to the (n+1)th photoelectric conversion unitsegment 10′_((n+1)). This can certainly prevent the flow of charge fromthe first photoelectric conversion unit segment 10′₁ to the firstelectrode 21. Furthermore, when the state shifts to V₂₂<V₂₁ in thecharge transfer period, the flow of charge from the first photoelectricconversion unit segment 10′₁ to the first electrode 21 and the flow ofcharge from the (n+1)th photoelectric conversion unit segment10′_((n+1)) to the nth photoelectric conversion unit segment 10′_(n) canbe certainly secured.

In this way, in the imaging element of Embodiment 8, the thicknesses ofthe photoelectric conversion layer segments gradually change from thefirst photoelectric conversion unit segment to the Nth photoelectricconversion unit segment. Alternatively, the cross-sectional area of thestacked part of the charge storage electrode, the insulating layer, theinorganic oxide semiconductor material layer, and the photoelectricconversion layer when the stacked part is cut in the YZ virtual planechanges in accordance with the distance from the first electrode.Therefore, a kind of charge transfer gradient is formed, and the chargegenerated by the photoelectric conversion can be more easily andcertainly transferred.

In for the first electrode 21, the charge storage electrode 24, theinsulating layer 82, the inorganic oxide semiconductor material layer23B, and the photoelectric conversion layer 23A in the imaging elementof Embodiment 8, a conductive material layer for forming the chargestorage electrode 24′₃ is deposited on the interlayer insulating layer81 first The conductive material layer is patterned, and the conductivematerial layer is left in the region where the photoelectric conversionunit segments 10′₁, 10′₂, and 10′₃ and the first electrode 21 are to beformed. In this way, part of the first electrode 21 and the chargestorage electrode 24′₃ can be obtained. Next, a conductive materiallayer for forming the charge storage electrode 24′₂ is deposited on theentire surface, and the conductive material layer is patterned. Theconductive material layer is left in the region where the photoelectricconversion unit segments 10∝₁ and 10′₂ and the first electrode 21 are tobe formed. In this way, part of the first electrode 21 and the chargestorage electrode 24′₂ can be obtained. Next, a conductive materiallayer for forming the charge storage electrode 24′₁ is deposited on theentire surface, and the conductive material layer is patterned. Theconductive material layer is left in the region where the photoelectricconversion unit segment 10′₁ and the first electrode 21 are to beformed. In this way, the first electrode 21 and the charge storageelectrode 24∝₁ can be obtained. Next, the insulating layer 82 isconformally deposited on the entire surface. Furthermore, the inorganicoxide semiconductor material layer 23B and the photoelectric conversionlayer 23A are formed on the insulating layer 82, and a planarizationprocess is applied to the photoelectric conversion layer 23A. In thisway, the photoelectric conversion unit segments 10∝₁, 10′₂, and 10′₃ canbe obtained.

Embodiment 9

Embodiment 9 relates to the imaging element of the third configuration.FIG. 41 illustrates a schematic partial cross-sectional view of theimaging element of Embodiment 9. In the imaging element of Embodiment 9,the materials included in the insulating layer segments vary betweenadjacent photoelectric conversion unit segments. Here, the values ofdielectric constant of the materials included in the insulating layersegments are gradually reduced from the first photoelectric conversionunit segment 10∝₁ to the Nth photoelectric conversion unit segment10′_(N). In the imaging element of Embodiment 9, the same potential maybe applied to all of the N charge storage electrode segments, or adifferent potential may be applied to each of the N charge storageelectrode segments in the latter case, the charge storage electrodesegments 24′₁, 24′₂, and 24′₃ arranged apart from each other is onlyrequired to be connected to the vertical drive circuit 112 included inthe drive circuit through pad portions 641, 642, and 643 as described inEmbodiment 10.

In addition, by adopting the configuration, a kind of charge transfergradient is formed. When the state shifts to V₁₂≥V₁₁ in the chargestorage period, the nth photoelectric conversion unit segment can storemore charge than the (n+1)th photoelectric conversion unit segment.Furthermore, when the state shifts to V₂₂<V₂₁ in the charge transferperiod, the flow of charge from the first photoelectric conversion unitsegment to the first electrode and the flow of charge from the (n+1)thphotoelectric conversion unit segment to the nth photoelectricconversion unit segment can be certainly secured.

Embodiment 10

Embodiment 10 relates to the imaging element of the fourthconfiguration. FIG. 42 illustrates a schematic partial cross-sectionalview of the imaging element of Embodiment 10. In the imaging element ofEmbodiment 10, the materials included in the charge storage electrodesegments vary between adjacent photoelectric conversion unit segments.Here, the values of work function of the materials included in theinsulating layer segments are gradually increased from the firstphotoelectric conversion unit segment 10∝₁ to the Nth photoelectricconversion unit segment 10′_(N). In the imaging element of Embodiment10, the same potential may be applied to all of the N charge storageelectrode segments, or a different potential may be applied to each ofthe N charge storage electrode segments. In the latter case, the chargestorage electrode segments 24′₁, 24′₂, and 24′₃ can be connected to thevertical drive circuit 112 included in the drive circuit through the padportions 641, 642, and 643.

Embodiment 11

An imaging element of Embodiment 11 relates to the imaging element ofthe fifth configuration. FIGS. 43A, 43B, 44A, and 44B illustrateschematic plan views of the charge storage electrode segments inEmbodiment 11. FIG. 45 illustrates a schematic layout drawing of thefirst electrode and the charge storage electrode included in thephotoelectric conversion unit including the charge storage electrode andthe transistors of the control unit included in the imaging element ofEmbodiment 11. The schematic partial cross-sectional view of the imagingelement of Embodiment 11 is similar to the schematic partialcross-sectional view illustrated in FIG. 42 or 47. In the imagingelement of Embodiment 11, the areas of the charge storage electrodesegments gradually decrease from the first photoelectric conversion unitsegment 10∝₁ to the Nth photoelectric conversion unit segment 10′_(N).In the imaging element of Embodiment 11, the same potential may beapplied to all of the N charge storage electrode segments, or adifferent potential may be applied to each of the N charge storageelectrode segments. Specifically, as described in Embodiment 10, thecharge storage electrode segments 24′₁, 24′₂, and 24′₃ arranged apartfrom each other is only required to be connected to the vertical drivecircuit 112 included in the drive circuit through the pad portions 641,642, and 643.

In Embodiment 11, the charge storage electrode 24 includes the pluralityof charge storage electrode segments 24′₁, 24′₂, and 24′₃. The number ofcharge storage electrode segments can be equal to or greater than 2, andthe number is “3” in embodiment 11. In addition, the potential of thefirst electrode 21 is higher than the potential of the second electrode22 in the imaging element of Embodiment 11. That is, for example, apositive potential is applied to the first electrode 21, and a negativepotential is applied to the second electrode 22. Therefore, in thecharge transfer period, the potential applied to the charge storageelectrode segment 24′₁ positioned at a place closest to the firstelectrode 21 is higher than the potential applied to the charge storageelectrode segment 24′₃ positioned at a place farthest from the firstelectrode 21. In this way, a potential gradient is provided to thecharge storage electrode 24. Therefore, the electrons stopped in theregion of the inorganic oxide semiconductor material layer 235 and thelike facing the charge storage electrode 24 are more certainly read outto the first electrode 21 and further to the first floating diffusionlayer FD₁. That is, the charge stored in the inorganic oxidesemiconductor material layer 235 and the like is read out to the controlunit.

Furthermore, in the charge transfer period, the potential of the chargestorage electrode segment 24′₃<the potential of the charge storageelectrode segment 24′₂<the potential of the charge storage electrodesegment 24′₁ holds. In this way, the electrons stopped in the region ofthe inorganic oxide semiconductor material layer 23B and the like can beread out to the first floating diffusion layer FD₁ all at once.Alternatively, in the charge transfer period, the potential of thecharge storage electrode segment 24′₃, the potential of the chargestorage electrode segment 24′₂, and the potential of the charge storageelectrode segment 24′₁ are gradually changed (that is, changed step-wiseor in a slope shape). In this way, the electrons stopped in the regionof the inorganic oxide semiconductor material layer 23B and the likefacing the charge storage electrode segment 24′₃ are moved to the regionof the inorganic oxide semiconductor material layer 23B and the likefacing the charge storage electrode segment 24′₂. Then, the electronsstopped in the region of the inorganic oxide semiconductor materiallayer 23B and the like facing the charge storage electrode segment 24′₂are moved to the region of the inorganic oxide semiconductor materiallayer 23B and the like facing the charge storage electrode segment 24′₁.Then, the electrons stopped in the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode segment 24∝₁ can be certainly read out to the first floatingdiffusion layer FD₁.

As in FIG. 46 illustrating a schematic layout drawing of the firstelectrode, the charge storage electrode, and the transistors of thecontrol unit included in the modified example of the imaging element ofEmbodiment 11, the other source/drain region 51B of the reset transistorTR3 _(rst) may be grounded, instead of connecting the other source/drainregion 51B to the power source V_(DD).

In the imaging element of Embodiment 11, a kind of charge transfergradient is also formed by adopting the configuration. That is, theareas of the charge storage electrode segments gradually decrease fromthe first photoelectric conversion unit segment 10′₁ to the Nthphotoelectric conversion unit segment 10′_(N). Therefore, when the stateshifts to V₁₂≥V₁₁ in the charge storage period, the nth photoelectricconversion unit segment can store more charge than the (n+1)thphotoelectric conversion unit segment. Further ore, when the stateshifts to V₂₂<V₂₁ in the charge transfer period, the flow of charge fromthe first photoelectric conversion unit segment to the first electrodeand the flow of charge from the (n+1)th photoelectric conversion unitsegment to the nth photoelectric conversion unit segment can becertainly secured.

Embodiment 12

Embodiment 12 relates to the imaging element of the sixth configuration.FIG. 47 illustrates a schematic partial cross-sectional view of theimaging element of Embodiment 12. In addition, FIGS. 48A and 48Billustrate schematic plan views of the charge storage electrode segmentsin Embodiment 12. The imaging element of Embodiment 12 includes thephotoelectric conversion unit including the first electrode 21, theinorganic oxide semiconductor material layer 23B, the photoelectricconversion layer 23A, and the second electrode 22 that are stacked. Thephotoelectric conversion unit further includes the charge storageelectrodes 24 (24″₁, 24″₂, and 24″₃) arranged apart from the firstelectrode 21 and arranged to face the inorganic oxide semiconductormaterial layer 23B through the insulating layer 82. The cross-sectionalarea of the stacked part of the charge storage electrodes 24 (24″₁,24″₂, and 24″₃), the insulating layer 82, the inorganic oxidesemiconductor material layer 23B, and the photoelectric conversion layer23A when the stacked part is out in the YZ virtual plane changes inaccordance with the distance from the first electrode 21, where the Zdirection is the stacking direction of the charge storage electrodes 24(24″₁, 24″₂, and 24″₃), the insulating layer 82, the inorganic oxidesemiconductor material layer 23B, and the photoelectric conversion layer23A, and the X direction is the direction away from the first electrode21.

Specifically, in the imaging element of Embodiment 12, the thickness ofthe cross section of the stacked part is constant, and the width of thecross section of the stacked part decreases with an increase in thedistance from the first electrode 21. Rote that the width maycontinuously decrease (see FIG. 48A) or may decrease step-wise (see FIG.48B).

In this way, in the imaging element of Embodiment 12, thecross-sectional area of the stacked part of the charge storageelectrodes 24 (24″₁, 24′'₂, and 24″₃), the insulating layer 82, and thephotoelectric conversion layer 23A when the stacked part is cut in theYZ virtual plane changes in accordance with the distance from the firstelectrode. Therefore, a kind of charge transfer gradient is formed, andthe charge generated by the photoelectric conversion can be more easilyand certainly transferred.

Embodiment 13

Embodiment 13 relates to the solid-state imaging apparatuses of thefirst configuration and the second configuration.

The solid-state imaging apparatus of Embodiment 13 includes

a photoelectric conversion unit including the first electrode 21, theinorganic oxide semiconductor material layer 23B, the photoelectricconversion layer 23A, and the second electrode 22 that are stacked, inwhich

the photoelectric conversion unit further includes a plurality ofimaging elements including the charge storage electrodes 24 arrangedapart from the first electrodes 21 and arranged to face the inorganicoxide semiconductor material layer 23k through the insulating layer 82,

a plurality of imaging elements are included in an imaging block, and

the first electrode 21 is shared by the plurality of imaging elementsincluded in an imaging element block.

Alternatively, the solid-state imaging apparatus of Embodiment 13includes a plurality of imaging elements described in Embodiments 1 to12.

In Embodiment 13, one floating diffusion layer is provided for theplurality of imaging elements. In addition, the timing of the chargetransfer period can be appropriately controlled to allow the pluralityof imaging elements to share one floating diffusion layer. Furthermore,in this case, the plurality of imaging elements can share one contacthole portion.

Note that the solid-state imaging apparatus of Embodiment 13 has aconfiguration and a structure substantially similar to the solid-stateimaging apparatuses described in Embodiments 1 to 12, except that theplurality of imaging elements included in the imaging element blockshare the first electrode 21.

FIG. 49 (Embodiment 13), FIG. 50 (first modified example of Embodiment13), FIG. 51 (second modified example of Embodiment 13), FIG. 52 (thirdmodified example of Embodiment 13), and FIG. 53 (fourth modified exampleof Embodiment 13) schematically illustrate arrangement states of thefirst electrodes 21 and the charge storage electrodes 24 in thesolid-state imaging apparatus of Embodiment 13. FIGS. 49, 50, 53, and 54illustrate sixteen imaging elements, and FIGS. 51 and 52 illustratetwelve imaging elements. In addition, two imaging elements are includedin the imaging element block. The imaging element blocks are surroundedand illustrated by dotted lines. Subscripts attached to the firstelectrodes 21 and the charge storage electrodes 24 are for distinctionof the first electrodes 21 and the charge storage electrodes 24. Thissimilarly applies to the following description. Furthermore, one on-chipmicro lens (not illustrated in FIGS. 49 to 58) is arranged on the upperside of one imaging element. Furthermore, in one imaging element block,two charge storage electrodes 24 are arranged across the first electrode21 (see FIGS. 49 and 50). Alternative one first electrode 21 is arrangedto face two charge storage electrodes 24 arranged side by side (seeFIGS. 53 and 54). That is, the first electrode is arranged adjacent tothe charge storage electrode of each imaging element. Alternatively, thefirst electrodes are arranged adjacent to the charge storage electrodesof part of the plurality of imaging elements and are not arrangedadjacent to the charge storage electrodes of the rest of the pluralityof imaging elements (see FIGS. 51 and 52). In this case, the movement ofcharge from the rest of the plurality of imaging elements to the firstelectrodes is movement through the part of the plurality of imagingelements. It is preferable that a distance A between the charge storageelectrode included in the imaging element and the charge storageelectrode included in the imaging element be longer than a distance Bbetween the first electrode and the charge storage electrode in theimaging element adjacent to the first electrode in order to certainlymove the charge from each imaging element to the first electrode. Inaddition, it is preferable that the farther the position of the imagingelement from the first electrode, the larger the value of the distanceA. Furthermore, in the examples illustrated in FIGS. 50, 52, and 54,charge movement control electrodes 27 are arranged between the pluralityof imaging elements included in the imaging element blocks. Arrangingthe charge movement control electrodes 27 can certainly suppress themovement of charge in the imaging element blocks positioned across thecharge movement control electrodes 27. Note that the potentials is onlyrequired to be set so that V₁₂>V₁₇ holds, where V₁₇ is the potentialapplied to the charge movement control electrodes 27.

The charge movement control electrodes 27 may be formed in the samelevel as the first electrodes 21 or the charge storage electrodes 24 ormay be formed in a different level (specifically, level on the lowerside of the first electrodes 21 or the charge storage electrodes 24) onthe first electrode side. In the former case, the distance between thecharge movement control electrode 27 and the photoelectric conversionlayer can be reduced, and the potential can be easily controlled. On theother hand, in the latter case, the distance between the charge movementcontrol electrode 27 and the charge storage electrode 24 can be reduced,and this is advantageous for miniaturization.

Hereinafter, an operation of the imaging element block including thefirst electrode 212 and two two charge storage electrodes 24 ₂₁ and 24₂₂ will be described.

In the charge storage period, the drive circuit applies a potentialV_(a) to the first electrode 21 ₂ and applies a potential V_(A) to thecharge storage electrodes 24 ₂₁ and 24 ₂₂. The light incident on thephotoelectric conversion layer 23A causes photoelectric conversion isthe photoelectric conversion layer 23A. The electron holes generated bythe photoelectric conversion are sent from the second electrode 22 tothe drive circuit through the wire V_(OU). On the other hand, thepotential of the first electrode 21 ₂ is higher than the potential ofthe second electrode 22. That is, for example, a positive potential isapplied to the first electrode 21 ₂, and a negative potential is appliedto the second electrode 22. Therefore, the potentials are set so thatV_(A)≥V_(a), preferably, V_(A)>V_(a), holds. As a result, the electronsgenerated by the photoelectric conversion are attracted to the chargestorage electrodes 24 ₂₁ and 24 ₂₂ and the electrons stop in the regionof the inorganic oxide semiconductor material layer 23B and the likefacing the charge storage electrodes 24 ₂₁ and 24 ₂₂. That is, thecharge is stored in the inorganic oxide semiconductor material layer 23Band the like. V_(A) is equal to or greater than V_(a), and therefore,the electrons generated inside of the photoelectric conversion layer 23Ado not move toward the first electrode 21 ₂. In the time course of thephotoelectric conversion, the potential in the region of the inorganicoxide semiconductor material layer 23B and the like facing the chargestorage electrodes 24 ₂₁ and 24 ₂₂ becomes a more negative value.

The reset operation is performed later in the charge storage period.This resets the potential of the first floating diffusion layer, and thepotential of the first floating diffusion layer shifts to the potentialV_(DD) of the power source.

After the completion of the reset operation, the charge is read out.That is, in the charge transfer period, the drive circuit applies apotential V_(b) to the first electrode 21 ₂, applies a potentialV_(21−B) to the charge storage electrode 24 ₂₁, and applies a potentialV_(22−B) to the charge storage electrode 24 ₂₂. Here, the potentials areset so that V_(21−B)<V_(b)<V_(22−B) holds. As a result, the electronsstopped in the region of the inorganic oxide semiconductor materiallayer 23B and the like facing the charge storage electrode 24 ₂₁ areread out to the first electrode 21 ₂ and further to the first floatingdiffusion layer. That is, the charge stored in the region of theinorganic oxide semiconductor material layer 23B and the like facing thecharge storage electrode 24 ₂₁ is read out to the control unit. Once thereading is completed, the potentials are set so thatV_(22−B)≤V_(21−B)<V_(b) holds. Note that in the examples illustrated inFIGS. 53 and 54, the potentials may be set so thatV_(22−B)<V_(b)<V_(21−B) holds. As a result, the electrons stopped in theregion of the inorganic oxide semiconductor material layer 23B and thelike facing the charge storage electrode 24 ₂₂ are read out to the firstelectrode 21 ₂ and further to the first floating diffusion layer.Furthermore, in the examples illustrated in FIGS. 51 and 52, theelectrons stopped in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₂₂ may be read out to the first floating diffusion layer through thefirst electrode 21 ₃ adjacent to the charge storage electrode 24 ₂₂. Inthis way, the charge stored in the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₂₂ is read out to the control unit. Note that when thereadout of the charge stored in the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₂₁ to the control unit is completed, the potential of thefirst floating diffusion layer may be reset.

FIG. 59A illustrates an example of reading and driving in the imagingelement block of Embodiment 13.

-   [Step-A]

Input of auto zero signal into comparator

-   [Step-B]

Reset operation of one shared floating diffusion layer

-   [Step-C]

Reading of P phase is imaging element corresponding to charge storageelectrode 24 ₂₁ and movement of charge to first electrode 21 ₂

-   [Step-D]

Reading of D phase in imaging element corresponding to charge storageelectrode 24 ₂₁ and movement of charge to first electrode 21 ₂

-   [Step-E]

Reset operation of one shared floating diffusion layer

-   [Step-F]

Input of auto zero signal into comparator [Step-G]

Reading of P phase in imaging element corresponding to charge storageelectrode 24 ₂₂ and movement of charge to first electrode 21 ₂

-   [Step-H]

Reading of D phase in imaging element corresponding to charge storageelectrode 24 ₂₁ and movement of charge to first electrode 21 ₂

The signals from two imaging elements corresponding to the chargestorage electrode 24 ₂₁ and the charge storage electrode 24 ₂₂ are readin this flow. Based on the correlated double sampling (CDS) process, thedifference between the reading of the P phase in [step-C] and thereading of the D phase in [step-D] is the signal from the imagingelement corresponding to the charge storage electrode 24 ₂₁. Thedifference between the reading of the P phase in [step-G] and thereading of the D phase in [step-H] is the signal from the imagingelement corresponding to the charge storage electrode 24 ₂₂.

Note that the operation of [step-E] may be skipped (see FIG. 59B), Inaddition, the operation of [step-F] may be skipped, and in this case,[step-G] can be further skipped (see FIG. 59C). The difference betweenthe reading of the P phase in [step-C] and the reading of the D phase in[step-D] is the signal from the imaging element corresponding to thecharge storage electrode 24 ₂₁. The difference between the reading ofthe D phase in [step-D] and the reading of the D phase in [step-H] isthe signal from the imaging element corresponding to the charge storageelectrode 24 ₂₂.

In modified examples of FIG. 55 (sixth modified example of Embodiment13) and FIG. 56 (seventh modified example of Embodiment 13)schematically illustrating arrangement states of the first electrodes 21and the charge storage electrodes 24, four imaging elements are includedin the imaging element block. The operations of the solid-state imagingapparatuses can be substantially similar to the operations of thesolid-state imaging apparatuses illustrated in FIGS. 49 to 54.

In an eighth modified example and a ninth modified example of FIGS. 57and 58 schematically illustrating arrangement states of the firstelectrodes 21 and the charge storage electrodes 24, sixteen imagingelements are included in the imaging element block. As illustrated inFIGS. 57 and 58, charge movement control electrodes 27A₁, 27A₂, and 27A₃are arranged between the charge storage electrode 24 ₂₁ and the chargestorage electrode 24 ₁₂, between the charge storage electrode 24 ₁₂ andthe charge storage electrode 24 ₁₃, and between the charge storageelectrode 24 ₁₃ and the charge storage electrode 24 ₁₄. In addition, asillustrated in FIG. 58, charge movement control electrodes 27B₂, 27B₂,and 27B₃ are arranged between the charge storage electrodes 24 ₂₂, 24₃₂, and 24 ₄₁ and the charge storage electrodes 24 ₂₂, 24 ₃₂, and 24 ₄₂,between the charge storage electrodes 24 ₂₂, 24 ₃₂, and 24 ₄₂ and thecharge storage electrodes 24 ₂₃, 24 ₃₃, and 24 ₄₃, and between thecharge storage electrodes 24 ₂₃, 24 ₁₃, and 24 ₄₃ and the charge storageelectrodes 24 ₂₄, 24 ₃₄, and 24 ₄₄. Furthermore, a charge movementcontrol electrode 27C is arranged between an imaging element block andan imaging element block. Furthermore, in each of the solid-stateimaging apparatuses, the sixteen charge storage electrodes 24 can becontrolled to read the charge stored in the inorganic oxidesemiconductor material layer 23B from the first electrode 21.

-   [Step 10]

Specifically, the charge stored in the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₁₁ is read from the first electrode 21 first Next, thecharge stored in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₁₂ is read from the first electrode 21 through the region of theinorganic oxide semiconductor material layer 23B and the like facing thecharge storage electrode 24 ₁₁. Next, the charge stored in the region ofthe inorganic oxide semiconductor material layer 23B and the like facingthe charge storage electrode 24 ₁₃ is read from the first electrode 21through the region of the inorganic oxide semiconductor material layer23B and the like facing the charge storage electrode 24 ₁₂ and thecharge storage electrode 24 ₁₁.

-   [Step-20]

Subsequently, the charge stored in the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₂₁ is moved to the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₁₁. The charge stored in the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₂₂ is moved to the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₁₂. The charge stored in the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₂₃ is moved to the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₁₃. The charge stored in the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 2424 is moved to the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 2414.

-   [Step-21]

The charge stored in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₃₁ is moved to the region of the inorganic oxide semiconductor materiallayer 23B and the like facing the charge storage electrode 24 ₂₁. Thecharge stored in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₃₂ is moved to the region of the inorganic oxide semiconductor materiallayer 23B and the like facing the charge storage electrode 24 ₂₂. Thecharge stored in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₃₃ is moved to the region of the inorganic oxide semiconductor materiallayer 23B and the like facing the charge storage electrode 24 ₂₃. Thecharge stored in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₃₄ is moved to the region of the inorganic oxide semiconductor materiallayer 23B and the like facing the charge storage electrode 24 ₂₄.

-   [Step-22]

The charge stored in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₂₂ is moved to the region of the inorganic oxide semiconductor materiallayer 23B and the like facing the charge storage electrode 24 ₁₁. Thecharge stored in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₄₂ is moved to the region of the inorganic oxide semiconductor materiallayer 23B and the like facing the charge storage electrode 24 ₃₂. Thecharge stored in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₄₃ is moved to the region of the inorganic oxide semiconductor materiallayer 23B and the like facing the charge storage electrode 24 ₃₃. Thecharge stored in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₄₄ is moved to the region of the inorganic oxide semiconductor materiallayer 23B and the like facing the charge storage electrode 24 ₃₄.

-   [Step-30]

Furthermore, [step-10] can be executed again to read the charge storedin the region of the inorganic oxide semiconductor material layer 23Band the like facing the charge storage electrode 24 ₂₁, the chargestored in the region of the inorganic oxide semiconductor material layer23B and the like facing the charge storage electrode 24 ₂₂, the chargestored in the region of the inorganic oxide semiconductor material layer23B and the like facing the charge storage electrode 24 ₂₃, and thecharge stored in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₂₄ through the first electrode 21.

-   [Step-40]

Subsequently, the charge stored in the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₂₁ is moved to the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₁₁. The charge stored in the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₂₂ is moved to the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₁₂. The charge stored in the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₂₃ is moved to the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₁₃. The charge stored in the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₂₄ is moved to the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₁₄.

-   [Step-41]

The charge stored in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₃₁ is moved to the region of the inorganic oxide semiconductor materiallayer 23B and the like facing the charge storage electrode 24 ₂₁. Thecharge stored in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₃₂ is moved to the region of the inorganic oxide semiconductor materiallayer 23B and the like facing the charge storage electrode 24 ₂₂. Thecharge stored in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₃₃ is moved to the region of the inorganic oxide semiconductor materiallayer 23B and the like facing the charge storage electrode 24 ₂₃. Thecharge stored in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₃₄ is moved to the region of the inorganic oxide semiconductor materiallayer 23B and the like facing the charge storage electrode 24 ₂₄.

-   [Step-50]

Furthermore, [step-10] can be executed again to read the charge storedin the region of the inorganic oxide semiconductor material layer 23Band the like facing the charge storage electrode 24 ₃₁, the chargestored in the region of the inorganic oxide semiconductor material layer23B and the like facing the charge storage electrode 24 ₃₂, the chargestored in the region of the inorganic oxide semiconductor material layer23B and the like facing the charge storage electrode 24 ₃₃, and thecharge stored in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₃₄ through the first electrode 21.

-   [Step-60]

Subsequently, the charge stored in the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₂₁ is moved to the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₁₁. The charge stored. In the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₂₂ is moved to the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₁₂. The charge stored is the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₂₃ is moved to the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₁₃. The charge stored in the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₂₄ is moved to the region of the inorganic oxidesemiconductor material layer 23B and the like facing the charge storageelectrode 24 ₁₄.

-   [Step-70]

Furthermore, [step-10] can be executed again to read the charge storedin the region of the inorganic oxide semiconductor material layer 23Band the like facing the charge storage electrode 24 ₄₁, the chargestored in the region of the inorganic oxide semiconductor material layer23B and the like facing the charge storage electrode 24 ₄₂, the chargestored in the region of the inorganic oxide semiconductor material layer23B and the like facing the charge storage electrode 24 ₄₃, and thecharge stored in the region of the inorganic oxide semiconductormaterial layer 23B and the like facing the charge storage electrode 24₄₄ through the first electrode 21.

In the solid-state imaging apparatus of Embodiment 13, the firstelectrode is shared by the plurality of imaging elements included in theimaging element block. This can simplify and miniaturize theconfiguration and the structure in the pixel region in which theplurality of imaging elements are arrayed. Note that the plurality ofimaging elements provided for one floating diffusion layer may include aplurality of imaging elements of first type or may include at least oneimaging element of first type and one or two or more imaging elements ofsecond type.

Embodiment 14

Embodiment 14 is a modification of Embodiment 13. In a solid-stateimaging apparatus of Embodiment 14 in FIGS. 60, 61, 62, and 63schematically illustrating arrangement states of the first electrode 21and the charge storage electrodes 24, two imaging elements are includedin the imaging element block. In addition, one on-chip micro lens 14 isarranged. On the upper side of the imaging element block. Note that inthe examples illustrated in FIGS. 61 and 63, the charge movement controlelectrode 27 is arranged between a plurality of imaging elementsincluded in the imaging element block.

For example, the photoelectric conversion layers corresponding to thecharge storage electrodes 24 ₁₁, 24 ₂₁, 24 ₃₁, and 24 ₄₁ included in theimaging element blocks are highly sensitive to the incident light fromthe upper right in the drawings. In addition, the photoelectricconversion layers corresponding to the charge storage electrodes 24 ₁₂,24 ₂₂, 24 ₃₂, and 24 ₄₂ included in the imaging element blocks arehighly sensitive to the incident light from the upper left in thedrawings. Therefore, for example, the imaging element including thecharge storage electrode 24 ₁₁ and the imaging element including thecharge storage electrode 24 ₁₂ can be combined to acquire an image planephase difference signal. In addition, the signal from the imagingelement including the charge storage electrode 24 ₁₁ and the signal fromthe imaging element including the charge storage electrode 24 ₁₂ can beadded, and the combination of the imaging elements can provide oneimaging element. Although the first electrode 21 ₁ is arranged betweenthe charge storage electrode 24 ₁₁ and the charge storage electrode 24₁₂ in the example illustrated in FIG. 60, one first electrode 21 ₁ canbe arranged to face two charge storage electrodes 24 ₁₁ and 24 ₁₂arranged side by side as in the example illustrated in FIG. 62 tothereby further improve the sensitivity.

Although the present disclosure has been described based on preferred.Embodiments, the present disclosure is not limited to these Embodiments.The structures, the configurations, the manufacturing conditions, themanufacturing methods, and the used materials of the stacked imagingelements, the imaging elements, and the solid-state imaging apparatusesdescribed in Embodiments are illustrative and can be appropriatelychanged. The imaging elements of Embodiments can be appropriatelycombined. For example, the imaging element of Embodiment 7, the imagingelement of Embodiment 8, the imaging element of Embodiment 9, theimaging element of Embodiment 10, and the imaging element of Embodiment11 can be arbitrarily combined, and the imaging element of Embodiment 7,the imaging element of Embodiment 8, the imaging element of Embodiment9, the imaging element of Embodiment 10, and the imaging element ofEmbodiment 12 can be arbitrarily combined.

The floating diffusion layers FD₁, FD₂, FD₃, 51C, 45C, and 46C can alsobe shared depending on the case.

As in a modified example of the imaging element described in Embodiment1 illustrated for example in FIG. 64, the first electrode 21 may extendin an opening portion 85A provided in the insulating layer 82, and thefirst electrode 21 may be connected to the inorganic oxide semiconductormaterial layer 23B.

Alternatively, as in a modified example of the imaging element describedin Embodiment 1 illustrated for example in FIG. 65 and as in an enlargedschematic partial cross-sectional view of the part and the like of thefirst electrode illustrated in FIG. 66A, the edge portion of the topsurface of the first electrode 21 is covered by the insulating layer 82,and the first electrode 21 is exposed on the bottom surface of anopening portion 85B. The side surface of the opening portion 85B has aslope extending from a first surface 82 a toward a second surface 82 b,in which the first surface 82 a is a surface of the insulating layer 82in contact with the top surface of the first electrode 21, and thesecond surface 82 b is a surface of the insulating layer 82 in contactwith the part of the inorganic oxide semiconductor material layer 23Bfacing the charge storage electrode 24. In this was, the side surface ofthe opening potion 85B is sloped, and the charge more smoothly movesfrom the inorganic oxide semiconductor material layer 23B to the firstelectrode 21. Note that although the side surface of the opening portion85B has rotational symmetry with respect to the axis of the openingportion 85B in the example illustrated in FIG. 66A, an opening portion85C may be provided such that the side surface of the opening portion85C sloped to extend from the first surface 82 a toward the secondsurface 82 b is positioned closer to the charge storage electrode 24 asillustrated in FIG. 66B. This makes the movement of charge difficultfrom the part of the inorganic oxide semiconductor material layer 23E onthe opposite side of the charge storage electrode 24 with respect to theopening portion 85C. In addition, although the side surface of theopening portion 85B is sloped to extend from the first surface 82 atoward the second surface 82 b, the edge portion of the side surface ofthe opening portion 85B in the second surface 82 b may be positionedoutside of the edge portion of the first electrode 21 as illustrated inFIG. 66A or may be positioned inside of the edge portion of the firstelectrode 21 as illustrated in FIG. 66C. The former configuration can beadopted to more easily transfer the charge, and the latter configurationcan be adopted to reduce the variations in the shape during theformation of the opening portions.

A reflow of an etching mask including a resist material formed to formthe opening portion in the insulating layer based on an etching methodcan slope the opening side surface of the etching mask, and the etchingmask can be used to etch the insulating layer 82 to form the openingportions 85B and 85G.

Alternatively, regarding the discharge electrode 26 described inEmbodiment 5, the inorganic oxide semiconductor material layer 23B canextend in a second opening portion 86A provided in the insulating layer82 and can be connected to the discharge electrode 26 as illustrated inFIG. 67. The edge portion of the top surface of the discharge electrode26 can be covered by the insulating layer 82, and the dischargeelectrode 26 can be exposed on the bottom surface of the second openingportion 86A. The side surface of the second opening portion 86A can besloped to extend from a third surface 82 c toward the second surface 82b, in which the third surface 82 c is a surface of the insulating layer82 in contact with the top surface of the discharge electrode 26, andthe second surface 82 b is a surface of the insulating layer 82 incontact with the part of the inorganic oxide semiconductor materiallayer 23B facing the charge storage electrode 24.

In addition, as in a modified example of the imaging element describedin Embodiment 1 illustrated for example in FIG. 68, the light may beincident from the second electrode 22 side, and a light shielding layer15 may be formed on the light incident side closer to the secondelectrode 22. Note that various wires provided on the light incidentside with respect to the photoelectric conversion layer may alsofunction as a light shielding layer.

Note that although the light shielding layer 15 is formed on the upperside of the second electrode 22 in the example illustrated in FIG. 68,that is, although the light shielding layer 15 is formed on the lightincident side closer to the second electrode 22 and on the upper side ofthe first electrode 21, the light shielding layer 15 may be arranged onthe surface of the light incident side of the second electrode 22 asillustrated in FIG. 69. In addition, the light shielding layer 15 may beformed on the second electrode 22 as illustrated in FIG. 70 depending onthe case.

Alternatively, the light may be incident from the second electrode 22side, and the light may not be incident on the first electrode 21.Specifically, as illustrated in FIG. 68, the light shielding layer 15 isformed on the light incident side closer to the second electrode 22 andon the upper side of the first electrode 21. Alternatively, asillustrated in FIG. 72, the on-chip micro lens 14 may be provided on theupper side of the charge storage electrode 24 and the second electrode22. The light incident on the on-chip micro lens 14 may be collected bythe charge storage electrode 24, and the light may not reach the firstelectrode 21. Note that in a case where the transfer control electrode25 is provided as described in Embodiment 4, the light may not beincident on the first electrode 21 and the transfer control electrode25. Specifically, as illustrated in FIG. 71, the light shielding layer15 may be formed on the upper side of the first electrode 21 and thetransfer control electrode 25. Alternatively, the light incident on theon-chip micro lens 14 may not reach the first electrode 21 or the firstelectrode 21 and the transfer control electrode 25.

The configurations and the structures can be adopted. Alternatively, thelight shielding layer 15 can be provided so that the light is incidenton only the part of the photoelectric conversion layer 23A positioned onthe upper side of the charge storage electrode 24, Alternatively, theon-chip micro lens 14 can be designed. In this way, the part of thephotoelectric conversion layer 23A positioned on the upper side of thefirst electrode 21 (or the upper side of the first electrode 21 and thetransfer control electrode 25) does not contribute to the photoelectricconversion. Therefore, all of the pixels can be more certainly reset allat once, and the global shutter function can be more easily realized.That is, in a driving method of the solid-state imaging apparatusincluding a plurality of imaging elements with the configurations andthe structures, the following steps are repeated:

releasing the charge in the first electrodes 21 all at once to theoutside of the system while storing the charge in the inorganic oxidesemiconductor material layers 23B and the like in all of the imagingelements; and then

transferring the charge stored in the inorganic oxide semiconductormaterial layers 231B and the like all at once to the first electrodes 21in all of the imaging elements, and after the completion of thetransfer, the imaging elements sequentially read the charge transferredto the first electrodes 21.

In the driving method of the solid-state imaging apparatus, the lightincident from the second electrode side is not incident on the firstelectrode in each imaging element. The charge in the first electrodes isreleased all at once to the outside of the system while the charge isstored in the inorganic oxide semiconductor material layers and the likein all of the imaging elements. Therefore, the first electrodes can becertainly reset at the same time in all of the imaging elements. Inaddition, subsequently, the charge stored in the inorganic oxidesemiconductor material layers and the like is transferred to the firstelectrodes all at once in all of the imaging elements. After thecompletion of the transfer, the imaging elements sequentially read thecharge transferred to the first electrodes. Therefore, the so-calledglobal shutter function can be easily realized.

Furthermore, in a modified example of Embodiment 4, a plurality oftransfer control electrodes may be provided from positions closest tothe first electrode 21 toward the charge storage electrode 24 asillustrated in FIG. 13. Note that FIG. 73 illustrates an example ofproviding two transfer control electrodes 25A and 25B. Furthermore, theon-chip micro lens 14 may be provided on the upper side of the chargestorage electrode 24 and the second electrode 22. The light incident onthe on-chip micro lens 14 may be collected by the charge storageelectrode 24, and the light may not reach the first electrode 21 and thetransfer control electrodes 25A and 25B.

In Embodiment 7 illustrated. In FIGS. 37 and 38, the thicknesses of thecharge storage electrode segments 24′₁, 24′₂, and 24′₃ are graduallyreduced to gradually increase the thicknesses of the insulating layersegments 82′2, 82′₂, and 82′₃. On the other hand, as in FIG. 74illustrating an enlarged schematic partial cross-sectional view of thestacked part of the charge storage electrode, the inorganic oxidesemiconductor material layer, the photoelectric conversion layer, andthe second electrode in a modified example of Embodiment 7, thethicknesses of the charge storage electrode segments 24′₁, 24′₂, and24′₃ may be constant, and the thicknesses of the insulating layersegments 82′₁, 82′₂, and 82′₃ may be gradually increased. Note that thethicknesses of the photoelectric conversion layer segments 23′₁, 23′₂,and 23′₃ are constant.

Further ore, in Embodiment 8 illustrated in FIG. 40, the thicknesses ofthe charge storage segments 24′₁, 24′₂, and 24′₃ are gradually reducedto gradually increase the thicknesses of the photoelectric conversionlayer segments 23′₁, 23′₂, and 23′₃. On the other hand, as in FIG. 75illustrating an enlarged schematic partial cross-sectional view of thestacked part of the charge storage electrode, the photoelectricconversion layer, and the second electrode in a modified example ofEmbodiment 8, the thicknesses of the charge storage electrode segments24′₁, 24′₂, and 24′₃ may be constant, and the thicknesses of theinsulating layer segments 82′₁, 82′₂, and 82′₃ may be gradually reducedto gradually increase the thicknesses of the photoelectric conversionlayer segments 23′₁, 23′₂, and 23′₃.

It is obvious that various modified examples described above can also beapplied to Embodiments 2 to 14.

In the examples described above, Embodiments are applied to the CMOSsolid-state imaging apparatus, in which the unit pixels that detect thesignal charge as a physical quantity according to the incident lightamount are arranged in a matrix. However, Embodiments are not limited tothe application to the CMOS solid-state imaging apparatus, andEmbodiments can also be applied to the CCD solid-state imagingapparatus. In the latter case, a vertical transfer register of CCDstructure transfers the signal charge in the vertical direction, and ahorizontal transfer register transfers the signal charge in thehorizontal direction. The charge is amplified, and a pixel signal (imagesignal) is output. In addition, Embodiments are not limited to thecolumn-type solid-state imaging apparatuses in general, in which thepixels are formed in a two-dimensional matrix, and a column signalprocessing circuit is arranged for each pixel column. Furthermore, theselection transistor may not be included depending on the case.

Furthermore, the imaging element of the present disclosure is notlimited to the application to the solid-state imaging apparatus thatdetects the distribution of the incident light amount of visible lightto obtain an image of the distribution. The imaging element can also beapplied to a solid-state imaging apparatus that takes an image of thedistribution of the incident amount of infrared rays, X rays, particles,or the like. Furthermore, in a broad sense, the imaging element can beapplied to solid-state imaging apparatuses (physical quantitydistribution detection apparatuses) in general, such as a fingerprintdetection sensor, that detects the distribution of another physicalquantity, such as pressure and capacitance, to obtain an image of thedistribution.

Furthermore, the imaging element is not limited to the solid-stateimaging apparatus that sequentially scans the unit pixels of the imagingregion row-by-row to read the pixel signals from the unit pixels. Theimaging element can also be applied to an X-Y address type solid-stateimaging apparatus that selects arbitrary pixels pixel-by-pixel and thatreads the pixel signals pixel-by-pixel from the selected pixels. Thesolid-state imaging apparatus may be formed as one chip or may be in aform of a module with an imaging function in which the imaging regionand the drive circuit or the optical system are packaged together.

In addition, the imaging element is not limited to the application tothe sold-state imaging apparatus, and the imaging element can also beapplied to an imaging apparatus. Here, the imaging apparatus denotes acamera system, such as a digital still camera and a video camera, or anelectronic device with an imaging function, such as a cell phone. Theimaging apparatus is in a form of a module mounted on the electronicdevice, that is, a camera module, in some cases.

FIG. 80 illustrates a conceptual diagram of an example in which asolid-state imaging apparatus 201 including the imaging element of thepresent disclosure is used in an electronic device (camera) 200. Theelectronic device 200 includes the solid-state imaging apparatus 201, anoptical lens 210, a shutter apparatus 211, a drive circuit. 212, and asignal processing circuit 213. The optical lens 210 uses image light(incident light) from an object to form an image on the imaging surfaceof the solid-state imaging apparatus 201. As a result, signal charge isstored in the solid-state imaging apparatus 201 for a certain period.The shutter apparatus 211 controls a light application period and alight shielding period for the solid-state imaging apparatus 201. Thedrive circuit 212 supplies drive signals for controlling a transferoperation and the like of the solid-state imaging apparatus 201 and ashutter operation of the shutter apparatus 211. The signal of thesolid-state imaging apparatus 201 is transferred based on the drivesignal (timing signal) supplied from the drive circuit 212. The signalprocessing circuit 213 executes various types of signal processing. Thevideo signal after the signal processing is stored in a storage medium,such as a memory, or output to a monitor. In the electronic device 200,the pixel size in the solid-state imaging apparatus 201 can beminiaturized, and the transfer efficiency can be improved. Therefore,the pixel characteristics can be improved in the electronic device 200.The electronic device 200 to which the solid-state imaging apparatus 201can be applied is not limited to the camera. The solid-state imagingapparatus 201 can be applied to a digital still camera, a camera modulefor mobile device, such as a cell phone, and other imaging apparatuses.

Note that the present disclosure can also be configured as follows.

-   [A01]<<Imaging Element: First Aspect>

An imaging element including:

a photoelectric conversion unit including a first electrode, aphotoelectric conversion layer, and a second electrode that are stacked,in which

an inorganic oxide semiconductor material layer is formed between thefirst electrode and the photoelectric conversion layer, and

the inorganic oxide semiconductor material layer includes at least twotypes of elements selected from the group consisting of indium,tungsten, tin, and zinc.

-   [A02]

The imaging element according to [A01], in which

the photoelectric conversion unit further includes an insulating layerand a charge storage electrode arranged apart from the first electrodeand arranged to face the inorganic oxide semiconductor material layerthrough the insulating layer.

The imaging element according to [A01] or [A02], in which

the inorganic oxide semiconductor material layer does not containgallium atoms.

-   [A04]

The imaging element according to [A01] or [A02], in which

the inorganic oxide semiconductor material layer includesindium-tungsten oxide (IWO), indium-tungsten-zinc oxide (IWZO),indium-tin-zinc oxide (ITZO), or zinc-tin oxide (ZTO).

The imaging element according to [A01] or [A02], in which

the inorganic oxide semiconductor material layer includesindium-tungsten-zinc oxide (IWZO).

-   [A06]

The imaging element according to [A01] or [A02], in which

the inorganic oxide semiconductor material layer includesindium-tungsten oxide (IWO).

-   [A07]

The imaging element according to any one of [A01] to [A06], in which

a LUMO value E₁ of a material included in a part of the photoelectricconversion layer positioned near the inorganic oxide semiconductormaterial layer and a LUMO value E₂ of a material included in theinorganic oxide semiconductor material layer satisfy the followingexpression.

E₁−E₂<0.2 eV

-   [A08]

The imaging element according to [A07], in which the LUMO value E₁ ofthe material included in the part of the photoelectric conversion layerpositioned near the inorganic oxide semiconductor material layer and theLUMO value E₂ of the material included in the inorganic oxidesemiconductor material layer satisfy the following expression.

E₁−E₂<0.1 eV

-   [A09]

The imaging element according to any one of [A01] to [A08], in which

the mobility of the material included is the inorganic oxidesemiconductor material layer is equal to or greater than 10 cm²/V·s.

-   [10] <<Imaging Element: Second Aspect>>

An imaging element including:

a photoelectric conversion unit including a first electrode, aphotoelectric conversion layer, and a second electrode that are stacked,in which

as inorganic oxide semiconductor material layer is formed between thefirst electrode and the photoelectric conversion layer, and

a LUMO value E₁ of a material included in a part of the photoelectricconversion layer positioned near the inorganic oxide semiconductormaterial layer and a LUMO value E₂ of a material included in theinorganic oxide semiconductor material layer satisfy the followingexpression.

E₁−E₂<0.2 eV

The imaging element according to [A10], in which the LUMO value E₁ ofthe material included in the part of the photoelectric conversion layerpositioned near the inorganic oxide semiconductor material layer and theLUMO value E₂ of the material included in the inorganic oxidesemiconductor material layer satisfy the following expression.

E₁−E₂<0.1 eV

-   [A12 ]

The imaging element according to [A10] or [A11], in which

the mobility of the material included in the inorganic oxidesemiconductor material layer is equal to or greater than 10 cm²/V·s.

-   [A13] <<Imaging Element: Third Aspect>>

An imaging element including

a photoelectric conversion unit including a first electrode, aphotoelectric conversion layer, and a second electrode that are stacked,in which

an inorganic oxide semiconductor material layer is formed between thefirst electrode and the photoelectric conversion layer, and

the mobility of a material included in the inorganic oxide semiconductormaterial layer is equal to or greater than 10 cm²/V·s.

-   [A14]

The imaging element according to any one of [A01] to [A11], in which

the inorganic oxide semiconductor material layer is amorphous.

-   [A15]

The imaging element according to any one of [A01] to [A14], in which

the thickness of the inorganic oxide semiconductor material layer is1×10⁻⁸ m to 1.5×10⁻⁷ m.

-   [A16]

The imaging element according to any one of [A01] to [A15], in which

light is incident from the second electrode,

surface roughness Ra of the inorganic oxide semiconductor material layerin an interface between the photoelectric conversion layer and theinorganic oxide semiconductor material layer is equal to or smaller than1.5 nm, and a value of root means square roughness Rq of the inorganicoxide semiconductor material layer is equal to or smaller than 2.5 nm.

-   [B01]

The imaging element according to any one of [A01] to [A16], in which

the photoelectric conversion unit further includes an insulating layerand a charge storage electrode arranged apart from the first electrodeand arranged to face the inorganic oxide semiconductor material layerthrough the insulating layer.

-   [B02]

The imaging element according to [B01], further including

a semiconductor substrate, in which

the photoelectric conversion unit is arranged on an upper side of thesemiconductor substrate.

-   [B03]

The imaging element according to [B01] or [B02], in which

the first electrode extends in an opening portion provided in theinsulating layer and is connected to the inorganic oxide semiconductormaterial layer.

-   [B04]

The imaging element according to [B01] or [B02], in which

the inorganic oxide semiconductor material layer extends in an openingportion provided in the insulating layer and is connected to the firstelectrode.

-   [B05]

The imaging element according to [B04], in which

an edge portion of a top surface of the first electrode is covered bythe insulating layer, the first electrode is exposed on a bottom surfaceof the opening portion, and

a side surface of the opening portion is sloped to extend from a firstsurface toward a second surface, where the first surface is a surface ofthe insulating layer in contact with the top surface of the firstelectrode, and the second surface is a surface of the insulating layerin contact with a part of the inorganic oxide semiconductor materiallayer facing the charge storage electrode.

-   [B06]

The imaging element according to [B05], in which the side surface of theopening portion sloped to extend from the first surface toward thesecond surface is positioned on a charge storage electrode side.

-   [B07] <<Control of Potentials of First Electrode and Charge Storage    Electrode>>

The imaging element according to any one of [B01] to [B06]], furtherincluding:

a control unit provided on the semiconductor substrate and including adrive circuit, in which the first electrode and the charge storageelectrode are connected to the drive circuit, in a charge storageperiod, the drive circuit applies a potential V₁₁ to the first electrodeand applies a potential V₁₂ to the charge storage electrode, and chargeis stored in the inorganic oxide semiconductor material layer, and

in a charge transfer period, the drive circuit applies a potential V₂₁to the first electrode and applies a potential V₂₂ to the charge storageelectrode, and the charge stored is the inorganic oxide semiconductormaterial layer is read out to the control unit through the firstelectrode, where

the potential of the first electrode is higher than the potential of thesecond electrode, and V₁₂≥V₁₁ and V₂₂<V₂₁ hold.

[B08] <<Transfer Control Electrode>>

The imaging element according to any one of [B01] to [B06], furtherincluding:

a transfer control electrode arranged between the first electrode andthe charge storage electrode, arranged apart from the first electrodeand the charge storage electrode, and arranged to face the inorganicoxide semiconductor material layer through the insulating layer.

[B09] <<Control of Potentials of First Electrode, Charge StorageElectrode, and Transfer Control Electrode >>

The imaging element according to [B08], further including

a control unit provided on the semiconductor substrate and including adrive circuit, in which

the first electrode, the charge storage electrode, and the transfercontrol circuit are connected to the drive circuit, in a charge storageperiod, the drive circuit applies a potential V₁₁ to the firstelectrode, applies a potential V₁₂ to the charge storage electrode, andapplies a potential V₁₃ to the transfer control electrode, and charge isstored in the inorganic oxide semiconductor material layer, and

in a charge transfer period, the drive circuit applies a potential V₂₁to the first electrode, applies a potential V₂₂ to the charge storageelectrode, and applies a potential V₂₃ to the transfer controlelectrode, and the charge stored in the inorganic oxide semiconductormaterial layer is read out to the control unit through the firstelectrode, where

the potential of the first electrode is higher than the potential of thesecond electrode, and V₁₂>V₁₃ and V₂₂≤V₂₃≤V₂₁ hold.

-   [B10] <<Discharge Electrode>>

The imaging element according to any one of [B01] to [B09], furtherincluding

a discharge electrode connected to the inorganic oxide semiconductormaterial layer and arranged apart from the first electrode and thecharge storage electrode.

-   [B11]

The imaging element according to [B10], in which

the discharge electrode is arranged to surround the first electrode andthe charge storage electrode.

-   [B12 ]

The imaging element according to [B10] or [B11], in which

the inorganic oxide semiconductor material layer extends in a secondopening portion provided on the insulating layer and is connected to thedischarge electrode,

an edge portion of a top surface of the discharge electrode is coveredby the insulating layer,

the discharge electrode is exposed on a bottom surface of the secondopening,

a side surface of the second opening portion is sloped to extend from athird surface toward a second surface, where the third surface is asurface of the insulating layer in contact with the top surface of thedischarge electrode, and the second surface is a surface of theinsulating layer in contact with a part of the inorganic oxidesemiconductor material layer facing the charge storage electrode.

-   [B13] <<Control of Potentials of First Electrode, Charge Storage    Electrode, and Discharge Electrode>>

The imaging element according to any one of [B10] to [B12], furtherincluding:

a control unit provided on the semiconductor substrate and including adrive circuit, in which

the first electrode, the charge storage electrode, and the dischargeelectrode are connected to the drive circuit,

in a charge storage period, the drive circuit applies a potential V₁₁ tothe first electrode, applies a potential V₁₂ to the charge storageelectrode, and applies a potential V₁₄ to the discharge electrode, andcharge is stored in the inorganic oxide semiconductor material layer,and

in a charge transfer period, the drive circuit applies a potential V₂₁to the first electrode, applies a potential V₂₂ to the charge storageelectrode, and applies a potential V₂₄ to the discharge electrode, andthe charge stored in the inorganic oxide semiconductor material layer isread out to the control unit through the first electrode, where

the potential of the first electrode is higher than the potential of thesecond electrode, and V₁₄>V₁₁ and V₂₄<V₂₁ hold.

-   [B14] <<Charge Storage Electrode Segment>>

The imaging element according to any one of [B01] to [B13], in which

the charge storage electrode includes a plurality of charge storageelectrode segments.

-   [B15]

The imaging element according to [B14], in which

in a case where the potential of the first electrode is higher than thepotential of the second electrode, a potential applied to a chargestorage electrode segment positioned at a place closest to the firstelectrode is higher than a potential applied to a charge storageelectrode segment positioned at a place farthest from the firstelectrode in the charge transfer period, and

in a case where the potential of the first electrode is lower than thepotential of the second electrode, the potential applied to the chargestorage electrode segment positioned at the place closest to the firstelectrode is lower than the potential applied to the charge storageelectrode segment positioned at the place farthest from the firstelectrode in the charge transfer period.

-   [B16]

The imaging element according to any one of [B01] to [B15], in which

at least a floating diffusion layer and an amplification transistorincluded in the control unit are provided on the semiconductorsubstrate, and

the first electrode is connected to the floating diffusion layer and agate portion of the amplification transistor.

-   [B17]

The imaging element according to [B16], in which

a reset transistor and a selection transistor included in the controlunit are further provided on the semiconductor substrate,

the floating diffusion layer is connected to one source/drain region ofthe reset transistor,

one source/drain region of the amplification transistor is connected toone source/drain region of the selection transistor, and anothersource/drain region of the selection transistor is connected to a signalline.

-   [B18]

The imaging element according to any one of [B01] to [B17], in which

the size of the charge storage electrode is larger than the firstelectrode.

-   [B19]

The imaging element according to any one of [B01] to [B18], in which

light is incident from a second electrode side, and a light shieldinglayer is formed on a light incident side closer to the second electrode.

-   [B20]

The imaging element according to any one of [B01] to [B18], in which

light is incident from a second electrode side, and the light is notincident on the first electrode.

-   [B21]

The imaging element according to [B20], in which a light shielding layeris formed on a light

incident side closer to the second electrode, on an upper side of thefirst electrode.

-   [B22]

The imaging element according to [B20], in which an on-chip micro lensis provided on an upper side of the charge storage electrode and thesecond electrode, and

light incident on the on-chip micro lens is collected by the chargestorage electrode.

-   [B23] <<Imaging Element: First Configuration>>

The imaging element according to any one of [B01] to [B22], in which

the photoelectric conversion unit includes N (where N≥2) photoelectricconversion unit segments, the inorganic oxide semiconductor materiallayer and the photoelectric conversion layer include N photoelectricconversion layer segments,

the insulating layer includes N insulating layer segments,

the charge storage electrode includes N charge storage electrodesegments,

an nth (where n=1, 2, 3, . . . N) photoelectric conversion unit segmentincludes an nth charge storage electrode segment, an nth insulatinglayer segment, and an nth photoelectric conversion layer segment,

the larger the value of n of the photoelectric conversion unit segment,the farther the position of the photoelectric conversion unit segmentfrom the first electrode, and

the thicknesses of the insulating layer segments gradually change fromthe first photoelectric conversion unit segment to the Nth photoelectricconversion unit segment.

-   [B24] <<Imaging Element: Second Configuration >>

The imaging element according to any one of [B01] to [B22], in which

the photoelectric conversion unit includes N (where N≥2) photoelectricconversion unit segments,

the inorganic oxide semiconductor material layer and the photoelectricconversion layer include N photoelectric conversion layer segments,

the insulating layer includes N insulating layer segments,

the charge storage electrode includes N charge storage electrodesegments,

an nth (where n=1, 2, 3, . . . N) photoelectric conversion unit segmentincludes an nth charge storage electrode segment, as nth insulatinglayer segment, and an nth photoelectric conversion layer segment,

the larger the value of n of the photoelectric conversion unit segment,the farther the position of the photoelectric conversion unit segmentfrom the first electrode, and

the thicknesses of the photoelectric conversion layer segments graduallychange from the first photoelectric conversion unit segment to the Nthphotoelectric conversion unit segment.

-   [B25] <<Imaging Element: Third Configuration>>

The imaging element according to any one of [B01] to [B22], in which

the photoelectric conversion unit includes N (where N≥2) photoelectricconversion unit segments,

the inorganic oxide semiconductor material layer and the photoelectricconversion layer include N photoelectric conversion layer segments,

the insulating layer includes N insulating layer segments,

the charge storage electrode includes N charge storage electrodesegments,

an nth (where n=1, 2, 3, . . . N) photoelectric conversion unit segmentincludes an nth charge storage electrode segment, an nth insulatinglayer segment, and an nth photoelectric conversion layer segment,

the larger the value of n of the photoelectric conversion unit segment,the farther the position of the photoelectric conversion unit segmentfrom the first electrode, and

materials included in the insulating layer segments vary betweenadjacent photoelectric conversion unit segments.

-   [B26]<<Imaging Element: Fourth Configuration>>

The imaging element according to any one of [B01] to [B22], in which

the photoelectric conversion unit includes N (where N≥2) photoelectricconversion unit segments,

the inorganic oxide semiconductor material layer and the photoelectricconversion layer include N photoelectric conversion layer segments,

the insulating layer includes N insulating layer segments,

the charge storage electrode includes N charge storage electrodesegments arranged apart from each other,

an nth (where n=1, 2, 3, . . . N) photoelectric conversion unit segmentincludes an nth charge storage electrode segment, an nth insulatinglayer segment, and an nth photoelectric conversion layer segment,

the larger the value of n of the photoelectric conversion unit segment,the farther the position of the photoelectric conversion unit segmentfrom the first electrode, and

materials included in the charge storage electrode segments vary betweenadjacent photoelectric conversion unit segments.

-   [B27] <<Imaging Element: Fifth Configuration>>

The imaging element according to any one of [B01] to [B22], in which

the photoelectric conversion unit includes N (where N≥2) photoelectricconversion unit segments,

the inorganic oxide semiconductor material layer and the photoelectricconversion layer include N photoelectric conversion layer segments,

the insulating layer includes N insulating layer segments,

the charge storage electrode includes N charge storage electrodesegments arranged apart from each other, an nth (where n=1, 2, 3, . . .N) photoelectric conversion unit segment includes an nth charge storageelectrode segment, an nth insulating layer segment, and an nthphotoelectric conversion layer segment,

the larger the value of n of the photoelectric conversion unit segment,the farther the position of the photoelectric conversion unit segmentfrom the first electrode, and

the areas of the charge storage electrode segments gradually decreasefrom the first photoelectric conversion unit segment to the Nthphotoelectric conversion unit segment.

-   [B28] <<Imaging Element: Sixth Configuration>>

The imaging element according to any one of [B01] to [B22], in which

the cross-sectional area of a stacked part of the charge storageelectrode, the insulating layer, the inorganic oxide semiconductormaterial layer, and the photoelectric conversion layer when the stackedpart is cut in a YZ virtual plane changes in accordance with thedistance from the first electrode, where a Z direction is a stackingdirection of the charge storage electrode, the insulating layer, theinorganic oxide semiconductor material layer, and the photoelectricconversion layer, and an X direction is a direction away from the firstelectrode.

-   [C01] <<Stacked Imaging Element>>

A stacked imaging element including at least one imaging elementaccording to any one of [A01] to [B28].

-   [D01] <<Solid-State Imaging Apparatus: First Aspect>>

A solid-state imaging apparatus including a plurality of imagingelements according to any one of [A01] to [B28].

-   [D02] <<Solid-State Imaging Apparatus: Second Aspect>>

A solid-state imaging apparatus including a plurality of stacked imagingelements according to [C01].

-   [E01] <<Solid-State Imaging Apparatus: First Configuration>>

A solid-state imaging apparatus including

a photoelectric conversion unit including a first electrode, aphotoelectric conversion layer, and a second electrode that are stacked,in which

the photoelectric conversion unit includes a plurality of imagingelements according to any one of [A01] to [B28],

a plurality of imaging elements are included in an imaging elementblock, and

the first electrode is shared by the plurality of imaging elementsincluded in the imaging element block

-   [E02] <<Solid-State Imaging Apparatus: Second Configuration>>

A solid-state imaging apparatus including:

a plurality of imaging elements according to any one of [A01] to [B28],in which

a plurality of imaging elements are included in an imaging elementblock, and

the first electrode is shared by the plurality of imaging elementsincluded in the imaging element block.

-   [E03]

The solid-state imaging apparatus according to [E01] or [E02], in which

one on-chip micro lens is arranged on an upper side of one imagingelement. [E04]

The solid-state imaging apparatus according to or [E02], in which

two imaging elements are included in the imaging element block, and

one on-chip micro lens is arranged on an upper side of the imagingelement block.

-   [E05]

The solid-state imaging element according to any one of [E01] to [E04],in which

one floating diffusion layer is provided for a plurality of imagingelements.

-   [E06]

The solid-state imaging apparatus according to any one of [E01] to[E05], in which

the first electrode is arranged adjacent to the charge storage electrodeof each imaging element.

-   [E07]

The solid-state imaging apparatus according to any one of [E01] to[E06], in which

the first electrode is arranged adjacent to the charge storageelectrodes of part of the plurality of imaging elements and is notarranged adjacent to the charge storage electrodes of the rest of theplurality of imaging elements.

-   [E08]

The solid-state imaging apparatus according to [E07], in which

the distance between the charge storage electrode included in theimaging element and the charge storage electrode included in the imagingelement is longer than the distance between the first electrode and thecharge storage electrode in the imaging element adjacent to the firstelectrode.

-   [F01] <<Driving Method of Solid-State Imaging Apparatus>>

A driving method of a solid-state imaging apparatus including aplurality of imaging elements, each of the plurality of imaging elementsincluding:

a photoelectric conversion unit including a first electrode, aphotoelectric conversion layer, and a second electrode that are stacked,in which

the photoelectric conversion unit further includes a charge storageelectrode arranged apart from the first electrode and arranged to facethe photoelectric conversion layer through an insulating layer,

the plurality of imaging elements have a structure in which light isincident from a second electrode side, and the light is not incident onthe first electrode,

the driving method of the solid-state imaging apparatus repeating thesteps of:

releasing charge in the first electrodes all at once to the outside of asystem while storing the charge in the inorganic oxide semiconductormaterial layers in all of the imaging elements; and

subsequently, transferring the charge stored in the inorganic oxidesemiconductor material layers all at once to the first electrodes in allof the imaging elements, and after the completion of the transfer,sequentially reading the charge transferred to the first electrodes inthe imaging elements.

REFERENCE SIGNS LIST

10′₁, 10′₂, 10′₃ . . . Photoelectric conversion unit segment, 13 . . .various constituent elements of imaging element positioned on lower sideof interlayer insulating layer, 14 . . . On-chip micro lens (OCL), 15 .. . Light shielding layer, 21 . . . First electrode, 22 . . . Second.electrode, 23A . . . Photoelectric conversion layer, 23B . . . Inorganicoxide semiconductor material layer, 23′₁, 23′₂, 23′₃ . . . Photoelectricconversion layer segments, 24, 24″₁, 24″₂, 24″, 24″₃ . . . Chargestorage electrode, 24A, 24B, 24C, 24′₁, 24′₂, 24′₃ . . . Charge storageelectrode segment, 25, 25A, 25B . . . Transfer control electrode (chargetransfer electrode), 26 . . . Discharge electrode, 27, 27A₁, 27A₂, 27A₃,27B₁, 27B₂, 27B₃, 27C . . . Charge movement control electrode, 41, 43 .. . n-type semiconductor region, 42, 44, 73 . . . p⁺ layer, 45, 46 . . .Gate portion of transfer transistor, 51 . . . Gate portion of resettransistor TR1 _(rst), 51A. . . . Channel formation region of resettransistor TR1 _(rst), 51B, 51C . . . Source/drain region of resettransistor TR1,_(rst), 52 . . . Gate portion of amplification transistorTR1 _(amp), 52A . . . Channel formation region of amplification.transistor TR1 _(amp), 52B, 52C. . . . Source/drain region ofamplification. transistor TR1 _(amp), 53 . . . Gate portion of selectiontransistor TP1,1, 53A . . . Channel formation region of selectiontransistor TR1,_(sel), 53B, 53C . . . Source/drain region of selection.transistor TR1 _(sel) , 61 . . . Contact hole portion, 62 . . . Wiringlayer, 63, 64, 68A . . . Pad portion, 65, 68B . . . Connection hole, 66,67, 69 . . . Connection portion, 70 Semiconductor substrate, 70A . . .First surface (front surface) of semiconductor substrate, 70B . . .Second surface (back surface) of semiconductor substrate, 71 Elementseparation region, 72 Oxide film, 74 HfO₂ film, 75 Insulating materialfilm, 76, 81 . . . Interlayer insulating layer, 82 . . . Insulatinglayer, 82′₁, 82′₂, 83′₃ . . . Insulating layer segment, 82 a . . . Firstsurface of insulating layer, 82 b . . . Second surface of insulatinglayer, 82 c Third surface of insulating layer, 83 . . . insulatinglayer, 85, 85A, 85B, 85C . . . Opening portion, 86, 86A . . . Secondopening portion, 100 . . . Solid-state imaging apparatus, 101 . . .Stacked imaging element, 111 . . . Imaging region, 112 . . . Verticaldrive circuit, 113 . . . Column signal processing circuit, 114 . . .Horizontal drive circuit, 115 . . . Output circuit, 116 . . . Drivecontrol circuit, 117 . . . Signal line (data output line), 118 . . .Horizonal signal line, 200 . . . Electronic device (camera), 201 . . .Solid-state imaging apparatus, 210 . . . Optical lens, 211 . . . Shutterapparatus, 212 . . . Drive circuit, 213 . . . Signal processing circuit,FDA, FD2, FD3, 45C, 46C . . . Floating diffusion layer, TR1 _(trs), TR2_(trs), TR3 _(trs) . . . Transfer transistor, TR1 _(rst), TR2 _(rst),TR3 _(rst) Reset transistor, TR1 _(amp), TR2 _(amp), TR3 _(amp) . . .Amplification transistor, TR1 _(sel), TR3 _(sel), TR3 _(sel) . . .Selection transistor, V_(DD) . . . Power source, TG₁, TG₂, TG₃ . . .Transfer gate line, RST₁, RST₂, RST₃ . . . Reset line, SEL₁, SEL₂, SEL₃. . . Selection line, VSL, VSL₁, VSL₂, VSL₃ . . . Signal line (dataoutput line), V_(OA), V_(OU) . . . Wire

What is claimed is:
 1. An imaging element comprising: a photoelectricconversion unit including a first electrode, a photoelectric conversionlayer, and a second electrode that are stacked, wherein an inorganicoxide semiconductor material layer is formed between the first electrodeand the photoelectric conversion layer, and the inorganic oxidesemiconductor material layer includes at least two types of elementsselected from the group consisting of indium, tungsten, tin, and zinc.2. The imaging element according to claim 1, wherein the photoelectricconversion unit further includes an insulating layer and a chargestorage electrode arranged apart from the first electrode and arrangedto face the inorganic oxide semiconductor material layer through theinsulating layer.
 3. The imaging element according to claim 1, whereinthe inorganic oxide semiconductor material layer does not containgallium atoms.
 4. The imaging element according to claim 1, wherein theinorganic oxide semiconductor material layer includes indium-tungstenoxide (IWO), indium-tungsten-zinc oxide (IWZO), indium-tin-zinc oxide(ITZO), or zinc-tin oxide (ZTO).
 5. The imaging element according toclaim 1, wherein the inorganic oxide semiconductor material layerincludes indium-tungsten-zinc oxide (IWZO).
 6. The imaging elementaccording to claim 1, wherein the inorganic oxide semiconductor materiallayer includes indium-tungsten oxide (IWO).
 7. The imaging elementaccording to claim 1, wherein a LUMO value E₁ of a material included ina part of the photoelectric conversion layer positioned near theinorganic oxide semiconductor material layer and a LUMO value E₂ of amaterial included in the inorganic oxide semiconductor material layersatisfy the following expression.E1−E2<0.2 eV
 8. The imaging element according to claim 7, wherein theLUMO value E₁ of the material included in the part of the photoelectricconversion layer positioned near the inorganic oxide semiconductormaterial layer and the LUMO value E₂ of the material included in theinorganic oxide semiconductor material layer satisfy the followingexpression.E1−E2<0.1 eV
 9. The imaging element according to claim 1, wherein amobility of the material included in the inorganic oxide semiconductormaterial layer is equal to or greater than 10 cm²/V·s.
 10. An imagingelement comprising: a photoelectric conversion unit including a firstelectrode, a photoelectric conversion layer, and a second electrode thatare stacked, wherein an inorganic oxide semiconductor material layer isformed between the first electrode and the photoelectric conversionlayer, and a LUMO value E₁ of a material included in a part of thephotoelectric conversion layer positioned near the inorganic oxidesemiconductor material layer and a LUMO value E₂ of a material includedin the inorganic oxide semiconductor material layer satisfy thefollowing expression.E1−E2<0.2 eV
 11. The imaging element according to claim 10, wherein theLUMO value E₁ of the material included in the part of the photoelectricconversion layer positioned near the inorganic oxide semiconductormaterial layer and the LUMO value E₂ of the material included in theinorganic oxide semiconductor material layer satisfy the followingexpression.E1−E2<0.1 eV
 12. The imaging element according to claim 10, wherein amobility of the material included in the inorganic oxide semiconductormaterial layer is equal to or greater than 10 cm²/V·s.
 13. An imagingelement comprising: a photoelectric conversion unit including a firstelectrode, a photoelectric conversion layer, and a second electrode thatare stacked, wherein an inorganic oxide semiconductor material layer isformed between the first electrode and the photoelectric conversionlayer, and the mobility of a material included in the inorganic oxidesemiconductor material layer is equal to or greater than 10 cm²/V·s. 14.The imaging element according to claim 1, wherein the inorganic oxidesemiconductor material layer is amorphous.
 15. The imaging elementaccording to claim 1, wherein a thickness of the inorganic oxidesemiconductor material layer is 1×10⁻⁸ m to 1.5×10⁻⁷ m.
 16. The imagingelement according to claim 1, wherein light is incident from the secondelectrode, surface roughness Ra of the inorganic oxide semiconductormaterial layer in an interface between the photoelectric conversionlayer and the inorganic oxide semiconductor material layer is equal toor smaller than 1.5 nm, and a value of root means square roughness Rq ofthe inorganic oxide semiconductor material layer is equal to or smallerthan 2.5 nm.
 17. A stacked imaging element comprising: at least oneimaging element according to claim
 1. 18. A solid-state imagingapparatus comprising: a plurality of imaging elements according toclaim
 1. 19. A solid-state imaging apparatus comprising: a plurality ofstacked imaging elements according to claim 17.